drm/xe/hw_engine_group: Fix potential leak

If we fail to allocate a workqueue we will leak kzalloc'ed group
object since it was designed to be kfree'ed in the drmm cleanup
action, but we didn't have a chance to register this action yet.

To avoid this leak allocate a group object using drmm_kzalloc()
and start using predefined drmm action to release the workqueue.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Francois Dugast <francois.dugast@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250627184143.1480-1-michal.wajdeczko@intel.com

Author: mwajdecz

drivers/gpu/drm/xe/xe_hw_engine_group.c

@@ -12,15 +12,6 @@
 #include "xe_hw_engine_group.h"
 #include "xe_vm.h"
 
-static void
-hw_engine_group_free(struct drm_device *drm, void *arg)
-{
-	struct xe_hw_engine_group *group = arg;
-
-	destroy_workqueue(group->resume_wq);
-	kfree(group);
-}
-
 static void
 hw_engine_group_resume_lr_jobs_func(struct work_struct *w)
 {
@@ -53,22 +44,22 @@ hw_engine_group_alloc(struct xe_device *xe)
 	struct xe_hw_engine_group *group;
 	int err;
 
-	group = kzalloc(sizeof(*group), GFP_KERNEL);
+	group = drmm_kzalloc(&xe->drm, sizeof(*group), GFP_KERNEL);
 	if (!group)
 		return ERR_PTR(-ENOMEM);
 
 	group->resume_wq = alloc_workqueue("xe-resume-lr-jobs-wq", 0, 0);
 	if (!group->resume_wq)
 		return ERR_PTR(-ENOMEM);
 
+	err = drmm_add_action_or_reset(&xe->drm, __drmm_workqueue_release, group->resume_wq);
+	if (err)
+		return ERR_PTR(err);
+
 	init_rwsem(&group->mode_sem);
 	INIT_WORK(&group->resume_work, hw_engine_group_resume_lr_jobs_func);
 	INIT_LIST_HEAD(&group->exec_queue_list);
 
-	err = drmm_add_action_or_reset(&xe->drm, hw_engine_group_free, group);
-	if (err)
-		return ERR_PTR(err);
-
 	return group;
 }