io_uring: add missing finish_wait() in io_sq_thread()

Add it to pair with prepare_to_wait() in an attempt to avoid
anything weird in the field.

Fixes: b41e9852 ("io_uring: add per-task callback handler")
Reported-by: syzbot+0c3370f235b74b3cfd97@syzkaller.appspotmail.com
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -5968,6 +5968,7 @@ static int io_sq_thread(void *data)
 				}
 				if (current->task_works) {
 					task_work_run();
+					finish_wait(&ctx->sqo_wait, &wait);
 					continue;
 				}
 				if (signal_pending(current))