drm/xe/eustall: Fix a possible pointer dereference after free

If devm_add_action_or_reset() isn't successful, xe_eu_stall_fini()
is invoked. So, unsuccessful return from devm_add_action_or_reset()
shouldn't dereference gt->eu_stall as xe_eu_stall_fini() already
frees it. Fix this issue.

Fixes: 9a0b11d4 ("drm/xe/eustall: Add support to init, enable and disable EU stall sampling")
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/eae49a414a7314921108e0388810aaee6261ad92.1741800396.git.harish.chegondi@intel.com

drivers/gpu/drm/xe/xe_eu_stall.c

@@ -222,13 +222,7 @@ int xe_eu_stall_init(struct xe_gt *gt)
 		goto exit_free;
 	}
 
-	ret = devm_add_action_or_reset(xe->drm.dev, xe_eu_stall_fini, gt);
-	if (ret)
-		goto exit_destroy;
-
-	return 0;
-exit_destroy:
-	destroy_workqueue(gt->eu_stall->buf_ptr_poll_wq);
+	return devm_add_action_or_reset(xe->drm.dev, xe_eu_stall_fini, gt);
 exit_free:
 	mutex_destroy(&gt->eu_stall->stream_lock);
 	kfree(gt->eu_stall);