Fix potential memory leak in ASN1 parsing code in low memory conditions

src/util-decode-asn1.c

@@ -346,6 +346,7 @@ Asn1Ctx *SCAsn1CtxNew(void) {
 
     ac->asn1_stack = SCMalloc(sizeof(Asn1Node *) * asn1_max_frames_config);
     if (ac->asn1_stack == NULL) {
+        SCFree(ac);
         return NULL;
     }
     memset(ac->asn1_stack, 0, sizeof(Asn1Node *) * asn1_max_frames_config);