drm/msm: unlock on error in get_sched_entity()

drm/msm: unlock on error in get_sched_entity()

BugLink: https://bugs.launchpad.net/bugs/1951822
[ Upstream commit 7425e8167507fe512d8ac0825acda4aebf0a7ca0 ]

Add a missing unlock on the error path if drm_sched_entity_init() fails.

Fixes: 68002469e571 ("drm/msm: One sched entity per process per priority")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20211011124005.GE15188@kili
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>