drm/radeon: fix userptr return value checking (v2)

Otherwise we print false warning from time to time.

v2: agd5f: rebase

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Jack Xiao <Jack.Xiao@amd.com>
CC: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
1 file changed