drm/virtio: use %llu format string form atomic64_t

The virtgpu driver prints the last_seq variable using the %ld or
%lu format string, which does not work correctly on all architectures
and causes this compiler warning on ARM:

drivers/gpu/drm/virtio/virtgpu_fence.c: In function 'virtio_timeline_value_str':
drivers/gpu/drm/virtio/virtgpu_fence.c:64:22: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'long long int' [-Wformat=]
snprintf(str, size, "%lu", atomic64_read(&fence->drv->last_seq));
^
drivers/gpu/drm/virtio/virtgpu_debugfs.c: In function 'virtio_gpu_debugfs_irq_info':
drivers/gpu/drm/virtio/virtgpu_debugfs.c:37:16: warning: format '%ld' expects argument of type 'long int', but argument 3 has type 'long long int' [-Wformat=]
seq_printf(m, "fence %ld %lld\n",
^

In order to avoid the warnings, this changes the format strings to %llu
and adds a cast to u64, which makes it work the same way everywhere.

Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/virtio/virtgpu_debugfs.c

···
 	struct drm_info_node *node = (struct drm_info_node *) m->private;
 	struct virtio_gpu_device *vgdev = node->minor->dev->dev_private;
 
-	seq_printf(m, "fence %ld %lld\n",
-		   atomic64_read(&vgdev->fence_drv.last_seq),
+	seq_printf(m, "fence %llu %lld\n",
+		   (u64)atomic64_read(&vgdev->fence_drv.last_seq),
 		   vgdev->fence_drv.sync_seq);
 	return 0;
 }

drivers/gpu/drm/virtio/virtgpu_fence.c

···
 {
 	struct virtio_gpu_fence *fence = to_virtio_fence(f);
 
-	snprintf(str, size, "%lu", atomic64_read(&fence->drv->last_seq));
+	snprintf(str, size, "%llu", (u64)atomic64_read(&fence->drv->last_seq));
 }
 
 static const struct fence_ops virtio_fence_ops = {