mxssb: Fix possible crash when memory allocation fail

In case the memory allocation fails in the command parser, there
will might remain some allocated memory upon return. Fix this.
Signed-off-by: Marek Vasut <marex@denx.de>

mxssb.c

@@ -624,7 +624,7 @@ static int sb_parse_cmds(struct sb_section_ctx *sctx)
 	while (insts--) {
 		cctx = calloc(1, sizeof(*cctx));
 		if (!cctx)
-			return -ENOMEM;
+			goto err;
 
 		if (!head)
 			head = cctx;