CLEANUP: conn_stream: rename the conn_stream's endp to sedesc

Just like for the appctx, this is a pointer to a stream endpoint descriptor,
so let's make this explicit and not confuse it with the full endpoint. There
are very few changes thanks to the preliminary refactoring of the flags
manipulation.
diff --git a/src/conn_stream.c b/src/conn_stream.c
index da81d27..e84021f 100644
--- a/src/conn_stream.c
+++ b/src/conn_stream.c
@@ -142,7 +142,7 @@
 		if (unlikely(!sedesc))
 			goto alloc_error;
 	}
-	cs->endp = sedesc;
+	cs->sedesc = sedesc;
 	sedesc->cs = cs;
 
 	return cs;
@@ -215,9 +215,9 @@
 {
 	sockaddr_free(&cs->src);
 	sockaddr_free(&cs->dst);
-	if (cs->endp) {
+	if (cs->sedesc) {
 		BUG_ON(!sc_ep_test(cs, SE_FL_DETACHED));
-		sedesc_free(cs->endp);
+		sedesc_free(cs->sedesc);
 	}
 	if (cs->wait_event.tasklet)
 		tasklet_free(cs->wait_event.tasklet);
@@ -232,7 +232,7 @@
 {
 	struct conn_stream *cs = *csp;
 
-	if (!cs->app && (!cs->endp || sc_ep_test(cs, SE_FL_DETACHED))) {
+	if (!cs->app && (!cs->sedesc || sc_ep_test(cs, SE_FL_DETACHED))) {
 		cs_free(cs);
 		*csp = NULL;
 	}
@@ -246,11 +246,12 @@
 int cs_attach_mux(struct conn_stream *cs, void *endp, void *ctx)
 {
 	struct connection *conn = ctx;
+	struct sedesc *sedesc = cs->sedesc;
 
-	cs->endp->se     = endp;
-	cs->endp->conn   = ctx;
-	sc_ep_set(cs, SE_FL_T_MUX);
-	sc_ep_clr(cs, SE_FL_DETACHED);
+	sedesc->se = endp;
+	sedesc->conn = ctx;
+	se_fl_set(sedesc, SE_FL_T_MUX);
+	se_fl_clr(sedesc, SE_FL_DETACHED);
 	if (!conn->ctx)
 		conn->ctx = cs;
 	if (cs_strm(cs)) {
@@ -288,7 +289,7 @@
  */
 static void cs_attach_applet(struct conn_stream *cs, void *endp)
 {
-	cs->endp->se = endp;
+	cs->sedesc->se = endp;
 	sc_ep_set(cs, SE_FL_T_APPLET);
 	sc_ep_clr(cs, SE_FL_DETACHED);
 	if (cs_strm(cs)) {
@@ -342,20 +343,20 @@
 	if (!cs)
 		return;
 
-	if (!cs->endp)
+	if (!cs->sedesc)
 		goto reset_cs;
 
 	if (sc_ep_test(cs, SE_FL_T_MUX)) {
 		struct connection *conn = __cs_conn(cs);
-		struct sedesc *endp = cs->endp;
+		struct sedesc *sedesc = cs->sedesc;
 
 		if (conn->mux) {
 			if (cs->wait_event.events != 0)
 				conn->mux->unsubscribe(cs, cs->wait_event.events, &cs->wait_event);
-			se_fl_set(endp, SE_FL_ORPHAN);
-			endp->cs = NULL;
-			cs->endp = NULL;
-			conn->mux->detach(endp);
+			se_fl_set(sedesc, SE_FL_ORPHAN);
+			sedesc->cs = NULL;
+			cs->sedesc = NULL;
+			conn->mux->detach(sedesc);
 		}
 		else {
 			/* It's too early to have a mux, let's just destroy
@@ -372,16 +373,16 @@
 		struct appctx *appctx = __cs_appctx(cs);
 
 		sc_ep_set(cs, SE_FL_ORPHAN);
-		cs->endp->cs = NULL;
-		cs->endp = NULL;
+		cs->sedesc->cs = NULL;
+		cs->sedesc = NULL;
 		appctx_shut(appctx);
 		appctx_free(appctx);
 	}
 
-	if (cs->endp) {
+	if (cs->sedesc) {
 		/* the cs is the only one one the endpoint */
-		cs->endp->se     = NULL;
-		cs->endp->conn   = NULL;
+		cs->sedesc->se     = NULL;
+		cs->sedesc->conn   = NULL;
 		sc_ep_clr(cs, ~SE_FL_APP_MASK);
 		sc_ep_set(cs, SE_FL_DETACHED);
 	}
@@ -464,9 +465,9 @@
 
 	/* The app is still attached, the cs will not be released */
 	cs_detach_endp(&cs);
-	BUG_ON(cs->endp);
-	cs->endp = new_endp;
-	cs->endp->cs = cs;
+	BUG_ON(cs->sedesc);
+	cs->sedesc = new_endp;
+	cs->sedesc->cs = cs;
 	sc_ep_set(cs, SE_FL_DETACHED);
 	return 0;
 }
@@ -484,7 +485,7 @@
 
 	DPRINTF(stderr, "registering handler %p for cs %p (was %p)\n", app, cs, cs_strm_task(cs));
 
-	appctx = appctx_new_here(app, cs->endp);
+	appctx = appctx_new_here(app, cs->sedesc);
 	if (!appctx)
 		return NULL;
 	cs_attach_applet(cs, appctx);