drm/xe: Check empty pinned BO list with lock held.

Use lock that is meant to use for accessing the BO pin list.
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240528115408.22094-1-nirmoy.das@intel.comSigned-off-by: Nirmoy Das <nirmoy.das@intel.com>

drivers/gpu/drm/xe/xe_bo.c

@@ -1758,11 +1758,10 @@ void xe_bo_unpin_external(struct xe_bo *bo)
 	xe_assert(xe, xe_bo_is_pinned(bo));
 	xe_assert(xe, xe_bo_is_user(bo));
 
-	if (bo->ttm.pin_count == 1 && !list_empty(&bo->pinned_link)) {
 	spin_lock(&xe->pinned.lock);
+	if (bo->ttm.pin_count == 1 && !list_empty(&bo->pinned_link))
 		list_del_init(&bo->pinned_link);
 	spin_unlock(&xe->pinned.lock);
-	}
 
 	ttm_bo_unpin(&bo->ttm);
 
@@ -1785,9 +1784,8 @@ void xe_bo_unpin(struct xe_bo *bo)
 		struct ttm_place *place = &(bo->placements[0]);
 
 		if (mem_type_is_vram(place->mem_type)) {
-			xe_assert(xe, !list_empty(&bo->pinned_link));
-
 			spin_lock(&xe->pinned.lock);
+			xe_assert(xe, !list_empty(&bo->pinned_link));
 			list_del_init(&bo->pinned_link);
 			spin_unlock(&xe->pinned.lock);
 		}