MINOR: applet: Make .init callback more generic

For now there is no much change. Only the appctx is passed as argument when
the .init callback function is called. And it is not possible to yield at
this stage. It is not a problem because the feature is not used. Only the
lua defines this callback function for the lua TCP/HTTP services. The idea
is to be able to use it for all applets to initialize the appctx context.
diff --git a/src/hlua.c b/src/hlua.c
index ee48323..ecc0762 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -9187,9 +9187,10 @@
 	return t;
 }
 
-static int hlua_applet_tcp_init(struct appctx *ctx, struct proxy *px, struct stream *strm)
+static int hlua_applet_tcp_init(struct appctx *ctx)
 {
 	struct stream_interface *si = cs_si(ctx->owner);
+	struct stream *strm = si_strm(si);
 	struct hlua *hlua;
 	struct task *task;
 	char **arg;
@@ -9197,7 +9198,7 @@
 
 	hlua = pool_alloc(pool_head_hlua);
 	if (!hlua) {
-		SEND_ERR(px, "Lua applet tcp '%s': out of memory.\n",
+		SEND_ERR(strm->be, "Lua applet tcp '%s': out of memory.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		return 0;
 	}
@@ -9208,7 +9209,7 @@
 	/* Create task used by signal to wakeup applets. */
 	task = task_new_here();
 	if (!task) {
-		SEND_ERR(px, "Lua applet tcp '%s': out of memory.\n",
+		SEND_ERR(strm->be, "Lua applet tcp '%s': out of memory.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		return 0;
 	}
@@ -9223,7 +9224,7 @@
 	 * Lua initialization cause 5% performances loss.
 	 */
 	if (!hlua_ctx_init(hlua, fcn_ref_to_stack_id(ctx->rule->arg.hlua_rule->fcn), task, 0)) {
-		SEND_ERR(px, "Lua applet tcp '%s': can't initialize Lua context.\n",
+		SEND_ERR(strm->be, "Lua applet tcp '%s': can't initialize Lua context.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		return 0;
 	}
@@ -9237,14 +9238,14 @@
 			error = lua_tostring(hlua->T, -1);
 		else
 			error = "critical error";
-		SEND_ERR(px, "Lua applet tcp '%s': %s.\n",
+		SEND_ERR(strm->be, "Lua applet tcp '%s': %s.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name, error);
 		return 0;
 	}
 
 	/* Check stack available size. */
 	if (!lua_checkstack(hlua->T, 1)) {
-		SEND_ERR(px, "Lua applet tcp '%s': full stack.\n",
+		SEND_ERR(strm->be, "Lua applet tcp '%s': full stack.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		RESET_SAFE_LJMP(hlua);
 		return 0;
@@ -9255,7 +9256,7 @@
 
 	/* Create and and push object stream in the stack. */
 	if (!hlua_applet_tcp_new(hlua->T, ctx)) {
-		SEND_ERR(px, "Lua applet tcp '%s': full stack.\n",
+		SEND_ERR(strm->be, "Lua applet tcp '%s': full stack.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		RESET_SAFE_LJMP(hlua);
 		return 0;
@@ -9265,7 +9266,7 @@
 	/* push keywords in the stack. */
 	for (arg = ctx->rule->arg.hlua_rule->args; arg && *arg; arg++) {
 		if (!lua_checkstack(hlua->T, 1)) {
-			SEND_ERR(px, "Lua applet tcp '%s': full stack.\n",
+			SEND_ERR(strm->be, "Lua applet tcp '%s': full stack.\n",
 			         ctx->rule->arg.hlua_rule->fcn->name);
 			RESET_SAFE_LJMP(hlua);
 			return 0;
@@ -9374,9 +9375,10 @@
  * an errors occurs and -1 if more data are required for initializing
  * the applet.
  */
-static int hlua_applet_http_init(struct appctx *ctx, struct proxy *px, struct stream *strm)
+static int hlua_applet_http_init(struct appctx *ctx)
 {
 	struct stream_interface *si = cs_si(ctx->owner);
+	struct stream *strm = si_strm(si);
 	struct http_txn *txn;
 	struct hlua *hlua;
 	char **arg;
@@ -9386,7 +9388,7 @@
 	txn = strm->txn;
 	hlua = pool_alloc(pool_head_hlua);
 	if (!hlua) {
-		SEND_ERR(px, "Lua applet http '%s': out of memory.\n",
+		SEND_ERR(strm->be, "Lua applet http '%s': out of memory.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		return 0;
 	}
@@ -9401,7 +9403,7 @@
 	/* Create task used by signal to wakeup applets. */
 	task = task_new_here();
 	if (!task) {
-		SEND_ERR(px, "Lua applet http '%s': out of memory.\n",
+		SEND_ERR(strm->be, "Lua applet http '%s': out of memory.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		return 0;
 	}
@@ -9416,7 +9418,7 @@
 	 * Lua initialization cause 5% performances loss.
 	 */
 	if (!hlua_ctx_init(hlua, fcn_ref_to_stack_id(ctx->rule->arg.hlua_rule->fcn), task, 0)) {
-		SEND_ERR(px, "Lua applet http '%s': can't initialize Lua context.\n",
+		SEND_ERR(strm->be, "Lua applet http '%s': can't initialize Lua context.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		return 0;
 	}
@@ -9430,14 +9432,14 @@
 			error = lua_tostring(hlua->T, -1);
 		else
 			error = "critical error";
-		SEND_ERR(px, "Lua applet http '%s': %s.\n",
+		SEND_ERR(strm->be, "Lua applet http '%s': %s.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name, error);
 		return 0;
 	}
 
 	/* Check stack available size. */
 	if (!lua_checkstack(hlua->T, 1)) {
-		SEND_ERR(px, "Lua applet http '%s': full stack.\n",
+		SEND_ERR(strm->be, "Lua applet http '%s': full stack.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		RESET_SAFE_LJMP(hlua);
 		return 0;
@@ -9448,7 +9450,7 @@
 
 	/* Create and and push object stream in the stack. */
 	if (!hlua_applet_http_new(hlua->T, ctx)) {
-		SEND_ERR(px, "Lua applet http '%s': full stack.\n",
+		SEND_ERR(strm->be, "Lua applet http '%s': full stack.\n",
 		         ctx->rule->arg.hlua_rule->fcn->name);
 		RESET_SAFE_LJMP(hlua);
 		return 0;
@@ -9458,7 +9460,7 @@
 	/* push keywords in the stack. */
 	for (arg = ctx->rule->arg.hlua_rule->args; arg && *arg; arg++) {
 		if (!lua_checkstack(hlua->T, 1)) {
-			SEND_ERR(px, "Lua applet http '%s': full stack.\n",
+			SEND_ERR(strm->be, "Lua applet http '%s': full stack.\n",
 			         ctx->rule->arg.hlua_rule->fcn->name);
 			RESET_SAFE_LJMP(hlua);
 			return 0;