drm/xe: Check return value of GGTT workqueue allocation

Workqueue allocation can fail, so check the return value of the GGTT
workqueue allocation and fail driver initialization if the allocation
fails.

Fixes: dd08ebf ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: stable@vger.kernel.org
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://lore.kernel.org/r/20251022005538.828980-2-matthew.brost@intel.com

Author: mbrost05

drivers/gpu/drm/xe/xe_ggtt.c

@@ -312,6 +312,9 @@ int xe_ggtt_init_early(struct xe_ggtt *ggtt)
 		ggtt->pt_ops = &xelp_pt_ops;
 
 	ggtt->wq = alloc_workqueue("xe-ggtt-wq", 0, WQ_MEM_RECLAIM);
+	if (!ggtt->wq)
+		return -ENOMEM;
+
 	__xe_ggtt_init_early(ggtt, xe_wopcm_size(xe));
 
 	err = drmm_add_action_or_reset(&xe->drm, ggtt_fini_early, ggtt);