drm/xe/hw_engine_group: Fix double write lock release in error path

In xe_hw_engine_group_get_mode(), a write lock is acquired before
calling switch_mode(), which in turn invokes
xe_hw_engine_group_suspend_faulting_lr_jobs().

On failure inside xe_hw_engine_group_suspend_faulting_lr_jobs(),
the write lock is released there, and then again in
xe_hw_engine_group_get_mode(), leading to a double release.

Fix this by keeping both acquire and release operation in
xe_hw_engine_group_get_mode().

Fixes: 770bd1d34113 ("drm/xe/hw_engine_group: Ensure safe transition between execution modes")
Cc: Francois Dugast <[e-mail]>
Signed-off-by: Shuicheng Lin <[e-mail]>
Reviewed-by: Francois Dugast <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lucas De Marchi <[e-mail]>
(cherry picked from commit 662d98b8b373007fa1b08ba93fee11f6fd3e387c)
Signed-off-by: Lucas De Marchi <[e-mail]>

drivers/gpu/drm/xe/xe_hw_engine_group.c

···
 
 		err = q->ops->suspend_wait(q);
 		if (err)
-			goto err_suspend;
+			return err;
 	}
 
 	if (need_resume)
 		xe_hw_engine_group_resume_faulting_lr_jobs(group);
 
 	return 0;
-
-err_suspend:
-	up_write(&group->mode_sem);
-	return err;
 }
 
 /**