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

Since commit a6aa8fca

 ("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 <syzbot+a225ee3df7e7f9372dbe@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=a225ee3df7e7f9372dbe
Fixes: a6aa8fca

 ("dma-buf/sw-sync: Reduce irqsave/irqrestore from known context")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/c2e46020-aaa6-4e06-bf73-f05823f913f0@I-love.SAKURA.ne.jp


Signed-off-by: Christian König <christian.koenig@amd.com>