dma_resv_trylock being successful doesn't guarantee that bo->tbo.base.resv
is not NULL, so check its validity before using it.
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>