moved dereference to its place


git-svn-id: https://asn1c.svn.sourceforge.net/svnroot/asn1c/trunk@578 59561ff5-6e30-0410-9f3c-9617f08c8826
diff --git a/skeletons/OCTET_STRING.c b/skeletons/OCTET_STRING.c
index c11bcae..c35588d 100644
--- a/skeletons/OCTET_STRING.c
+++ b/skeletons/OCTET_STRING.c
@@ -1231,7 +1231,7 @@
 				: &asn_DEF_OCTET_STRING_specs;
 	asn_struct_ctx_t *ctx = (asn_struct_ctx_t *)
 					((char *)st + specs->ctx_offset);
-	struct _stack *stck = (struct _stack *)ctx->ptr;
+	struct _stack *stck;
 
 	if(!td || !st)
 		return;
@@ -1245,6 +1245,7 @@
 	/*
 	 * Remove decode-time stack.
 	 */
+	stck = (struct _stack *)ctx->ptr;
 	if(stck) {
 		while(stck->tail) {
 			struct _stack_el *sel = stck->tail;