fixed asan memory leak ref issue

src/core/lib/channel/http_client_filter.c

@@ -297,7 +297,7 @@ static grpc_error *hc_mutate_op(grpc_exec_ctx *exec_ctx,
         const int k_url_safe = 1;
         const int k_multi_line = 0;
         const char *k_query_separator = "?";
-        const size_t k_query_separator_len = GPR_ARRAY_SIZE(k_query_separator);
+        const size_t k_query_separator_len = 1; /* strlen(k_query_separator) */
 
         grpc_slice path_slice =
             GRPC_MDVALUE(op->send_initial_metadata->idx.named.path->md);

src/core/lib/channel/http_server_filter.c

@@ -214,7 +214,7 @@ static grpc_error *server_filter_incoming_metadata(grpc_exec_ctx *exec_ctx,
 
     /* substitute path metadata with just the path (not query) */
     grpc_mdelem mdelem_path_without_query = grpc_mdelem_from_slices(
-        exec_ctx, GRPC_MDSTR_PATH, grpc_slice_sub(path_slice, 0, offset));
+        exec_ctx, GRPC_MDSTR_PATH, grpc_slice_sub_no_ref(path_slice, 0, offset));
 
     grpc_metadata_batch_substitute(exec_ctx, b, b->idx.named.path,
                                    mdelem_path_without_query);