dma-buf/sw-sync: don't enable IRQ from sync_print_obj()

Since commit a6aa8fc ("dma-buf/sw-sync: Reduce irqsave/irqrestore from
known context") by error replaced spin_unlock_irqrestore() with
spin_unlock_irq() for both sync_debugfs_show() and sync_print_obj() despite
sync_print_obj() is called from sync_debugfs_show(), lockdep complains
inconsistent lock state warning.

Use plain spin_{lock,unlock}() for sync_print_obj(), for
sync_debugfs_show() is already using spin_{lock,unlock}_irq().

Reported-by: syzbot <[email protected]>
Closes: https://syzkaller.appspot.com/bug?extid=a225ee3df7e7f9372dbe
Fixes: a6aa8fc ("dma-buf/sw-sync: Reduce irqsave/irqrestore from known context")
Signed-off-by: Tetsuo Handa <[email protected]>
Reviewed-by: Christian König <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Christian König <[email protected]>

Author: Tetsuo Handa

drivers/dma-buf/sync_debug.c

@@ -110,12 +110,12 @@ static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
 
 	seq_printf(s, "%s: %d\n", obj->name, obj->value);
 
-	spin_lock_irq(&obj->lock);
+	spin_lock(&obj->lock); /* Caller already disabled IRQ. */
 	list_for_each(pos, &obj->pt_list) {
 		struct sync_pt *pt = container_of(pos, struct sync_pt, link);
 		sync_print_fence(s, &pt->base, false);
 	}
-	spin_unlock_irq(&obj->lock);
+	spin_unlock(&obj->lock);
 }
 
 static void sync_print_sync_file(struct seq_file *s,