Valgrind fixes 1220 (#521)

* Release iterator upon error

* Free up ctx upon exception

Author: lantiga

src/dag.c

@@ -1176,6 +1176,7 @@ int RedisAI_DagRunSyntaxParser(RedisModuleCtx *ctx, RedisModuleString **argv, in
             if (!mangled_entry) {
                 AI_dictRelease(mangled_tensors);
                 AI_dictRelease(mangled_persisted);
+                AI_dictReleaseIterator(iter);
                 return RedisModule_ReplyWithError(ctx, "ERR PERSIST key cannot be found in DAG");
             }
             int *instance = AI_dictGetVal(mangled_entry);

src/libtorch_c/torch_c.cpp

@@ -347,7 +347,7 @@ extern "C" void *torchLoadModel(const char *graph, size_t graphlen, DLDeviceType
         *error = (char *)alloc(len * sizeof(char));
         strcpy(*error, e.what());
         (*error)[len - 1] = '\0';
-        // delete ctx;
+        delete ctx;
         return NULL;
     }
     return ctx;