Fix "copied for each invocation" warning

Bug: n/a
Test: cvd start --gpu_mode=gfxstream_guest_angle_host_swiftshader
Change-Id: I7dea81799eefd0c3a62ab22f95926a3a1bcd037e
diff --git a/stream-servers/virtio-gpu-gfxstream-renderer.cpp b/stream-servers/virtio-gpu-gfxstream-renderer.cpp
index dcf591e..e5911d7 100644
--- a/stream-servers/virtio-gpu-gfxstream-renderer.cpp
+++ b/stream-servers/virtio-gpu-gfxstream-renderer.cpp
@@ -865,7 +865,7 @@
         if (!callback) {
             return -EINVAL;
         }
-        mVirtioGpuTimelines->enqueueFence(ring, fence_id, callback);
+        mVirtioGpuTimelines->enqueueFence(ring, fence_id, std::move(callback));
 
         return 0;
     }