drm/amdkfd: Fix error handling in kfd_criu_restore_events

mutex_unlock before the exit label because all the error code paths that
jump there didn't take that lock. This fixes unbalanced locking errors
in case of restore errors.

Fixes: 40e8a766a7 ("drm/amdkfd: CRIU checkpoint and restore events")
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/amd/amdkfd/kfd_events.c

@@ -506,6 +506,7 @@ int kfd_criu_restore_event(struct file *devkfd,
 		ret = create_other_event(p, ev, &ev_priv->event_id);
 		break;
 	}
+	mutex_unlock(&p->event_mutex);
 
 exit:
 	if (ret)
@@ -513,8 +514,6 @@ exit:
 
 	kfree(ev_priv);
 
-	mutex_unlock(&p->event_mutex);
-
 	return ret;
 }