drm/ttm: fix documentation of ttm_bo_reserve

Previously, the comment was inconsistent. EDEADLK is what the ww_mutex
mechanism really returns.

Signed-off-by: Nicolai Hähnle <Nicolai.Haehnle@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
1 file changed