drm/radeon: fix radeon_fence_wait_empty_locked

Don't block forever if there is nothing to wait for.

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Rafa? Mi?ecki <zajec5@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
1 file changed