io_uring: fix break condition for __io_uring_register() waiting

Colin reports that there's unreachable code, since we only ever break
if ret == 0. This is correct, and is due to a reversed logic condition
in when to break or not.

Break out of the loop if we don't process any task work, in that case
we do want to return -EINTR.

Fixes: af9c1a44 ("io_uring: process task work in io_uring_register()")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -9511,15 +9511,15 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
 			ret = wait_for_completion_interruptible(&ctx->ref_comp);
 			if (!ret)
 				break;
-			if (io_run_task_work_sig() > 0)
-				continue;
+			ret = io_run_task_work_sig();
+			if (ret < 0)
+				break;
 		} while (1);
 
 		mutex_lock(&ctx->uring_lock);
 
 		if (ret) {
 			percpu_ref_resurrect(&ctx->refs);
-			ret = -EINTR;
 			goto out_quiesce;
 		}
 	}