CLEANUP: ssl/cli: use a local context for "set ssl crlfile"

Just like for "set ssl cafile", the command doesn't really need this
context which doesn't outlive the parsing function but it was there
for a purpose so it's maintained. Only 3 fields were used from the
appctx's ssl context: old_crlfile_entry, new_crlfile_entry, and path.
These ones were reinstantiated into a new "set_crlfile_ctx" struct.
It could have been merged with the one used in "set cafile" if the
fields had been renamed since cafile and crlfile are of the same
type (probably one of them ought to be renamed?).

None of these fields could be dropped as they are still shared with
other commands.
diff --git a/src/ssl_ckch.c b/src/ssl_ckch.c
index 5b31def..ad61fea 100644
--- a/src/ssl_ckch.c
+++ b/src/ssl_ckch.c
@@ -111,6 +111,12 @@
 	char *path;
 };
 
+/* CLI context used by "set crl-file" */
+struct set_crlfile_ctx {
+	struct cafile_entry *old_crlfile_entry;
+	struct cafile_entry *new_crlfile_entry;
+	char *path;
+};
 
 
 /********************  cert_key_and_chain functions *************************
@@ -3304,6 +3310,7 @@
 /* Parsing function of `set ssl crl-file` */
 static int cli_parse_set_crlfile(char **args, char *payload, struct appctx *appctx, void *private)
 {
+	struct set_crlfile_ctx *ctx = applet_reserve_svcctx(appctx, sizeof(*ctx));
 	char *err = NULL;
 	int errcode = 0;
 	struct buffer *buf;
@@ -3331,8 +3338,8 @@
 		goto end;
 	}
 
-	appctx->ctx.ssl.old_crlfile_entry = NULL;
-	appctx->ctx.ssl.new_crlfile_entry = NULL;
+	ctx->old_crlfile_entry = NULL;
+	ctx->new_crlfile_entry = NULL;
 
 	/* if there is an ongoing transaction */
 	if (crlfile_transaction.path) {
@@ -3342,43 +3349,43 @@
 			errcode |= ERR_ALERT | ERR_FATAL;
 			goto end;
 		}
-		appctx->ctx.ssl.old_crlfile_entry = crlfile_transaction.old_crlfile_entry;
+		ctx->old_crlfile_entry = crlfile_transaction.old_crlfile_entry;
 	}
 	else {
 		/* lookup for the certificate in the tree */
-		appctx->ctx.ssl.old_crlfile_entry = ssl_store_get_cafile_entry(buf->area, 0);
+		ctx->old_crlfile_entry = ssl_store_get_cafile_entry(buf->area, 0);
 	}
 
-	if (!appctx->ctx.ssl.old_crlfile_entry) {
+	if (!ctx->old_crlfile_entry) {
 		memprintf(&err, "%sCan't replace a CRL file which is not referenced by the configuration!\n",
 		          err ? err : "");
 		errcode |= ERR_ALERT | ERR_FATAL;
 		goto end;
 	}
 
-	if (!appctx->ctx.ssl.path) {
+	if (!ctx->path) {
 		/* this is a new transaction, set the path of the transaction */
-		appctx->ctx.ssl.path = strdup(appctx->ctx.ssl.old_crlfile_entry->path);
-		if (!appctx->ctx.ssl.path) {
+		ctx->path = strdup(ctx->old_crlfile_entry->path);
+		if (!ctx->path) {
 			memprintf(&err, "%sCan't allocate memory\n", err ? err : "");
 			errcode |= ERR_ALERT | ERR_FATAL;
 			goto end;
 		}
 	}
 
-	if (appctx->ctx.ssl.new_crlfile_entry)
-		ssl_store_delete_cafile_entry(appctx->ctx.ssl.new_crlfile_entry);
+	if (ctx->new_crlfile_entry)
+		ssl_store_delete_cafile_entry(ctx->new_crlfile_entry);
 
 	/* Create a new cafile_entry without adding it to the cafile tree. */
-	appctx->ctx.ssl.new_crlfile_entry = ssl_store_create_cafile_entry(appctx->ctx.ssl.path, NULL, CAFILE_CRL);
-	if (!appctx->ctx.ssl.new_crlfile_entry) {
+	ctx->new_crlfile_entry = ssl_store_create_cafile_entry(ctx->path, NULL, CAFILE_CRL);
+	if (!ctx->new_crlfile_entry) {
 		memprintf(&err, "%sCannot allocate memory!\n", err ? err : "");
 		errcode |= ERR_ALERT | ERR_FATAL;
 		goto end;
 	}
 
 	/* Fill the new entry with the new CRL. */
-	if (ssl_store_load_ca_from_buf(appctx->ctx.ssl.new_crlfile_entry, payload)) {
+	if (ssl_store_load_ca_from_buf(ctx->new_crlfile_entry, payload)) {
 		memprintf(&err, "%sInvalid payload\n", err ? err : "");
 		errcode |= ERR_ALERT | ERR_FATAL;
 		goto end;
@@ -3388,8 +3395,8 @@
 
 	/* if there wasn't a transaction, update the old CA */
 	if (!crlfile_transaction.old_crlfile_entry) {
-		crlfile_transaction.old_crlfile_entry = appctx->ctx.ssl.old_crlfile_entry;
-		crlfile_transaction.path = appctx->ctx.ssl.path;
+		crlfile_transaction.old_crlfile_entry = ctx->old_crlfile_entry;
+		crlfile_transaction.path = ctx->path;
 		err = memprintf(&err, "transaction created for CA %s!\n", crlfile_transaction.path);
 	} else {
 		err = memprintf(&err, "transaction updated for CA %s!\n", crlfile_transaction.path);
@@ -3398,7 +3405,7 @@
 	/* free the previous CRL file if there was a transaction */
 	ssl_store_delete_cafile_entry(crlfile_transaction.new_crlfile_entry);
 
-	crlfile_transaction.new_crlfile_entry = appctx->ctx.ssl.new_crlfile_entry;
+	crlfile_transaction.new_crlfile_entry = ctx->new_crlfile_entry;
 
 	/* creates the SNI ctxs later in the IO handler */
 
@@ -3406,12 +3413,10 @@
 	free_trash_chunk(buf);
 
 	if (errcode & ERR_CODE) {
-		ssl_store_delete_cafile_entry(appctx->ctx.ssl.new_crlfile_entry);
-		appctx->ctx.ssl.new_crlfile_entry = NULL;
-		appctx->ctx.ssl.old_crlfile_entry = NULL;
-
-		ha_free(&appctx->ctx.ssl.path);
-
+		ssl_store_delete_cafile_entry(ctx->new_crlfile_entry);
+		ctx->new_crlfile_entry = NULL;
+		ctx->old_crlfile_entry = NULL;
+		ha_free(&ctx->path);
 		HA_SPIN_UNLOCK(CKCH_LOCK, &ckch_lock);
 		return cli_dynerr(appctx, memprintf(&err, "%sCan't update %s!\n", err ? err : "", args[3]));
 	} else {