tu: Fix segfault in fail_submit KGSL path

Fixes: ec268fa5b6 ("tu/kgsl: Support u_trace and perfetto")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34749>
(cherry picked from commit 9dfd4a091c83d7a393f3ceac0607cc71e5df0ae8)

.pick_status.json

@@ -34,7 +34,7 @@
         "description": "tu: Fix segfault in fail_submit KGSL path",
         "nominated": true,
         "nomination_type": 2,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "ec268fa5b666a49adafc431dbc05b73bfd74526e",
         "notes": null

src/freedreno/vulkan/tu_knl_kgsl.cc

@@ -1328,7 +1328,7 @@ kgsl_queue_submit(struct tu_queue *queue, void *_submit,
    }
 
 fail_submit:
-   if (result != VK_SUCCESS) {
+   if (result != VK_SUCCESS && u_trace_submission_data) {
       mtx_lock(&queue->device->kgsl_profiling_mutex);
       tu_suballoc_bo_free(&queue->device->kgsl_profiling_suballoc,
                           &u_trace_submission_data->kgsl_timestamp_bo);