queue: ensure io_uring_submit() returns the system call value

A previous fix that ensured we pass back the right error messed
up the normal return, which is number of entries submitted.
This makes the poll test cases fail.

Fixes: 8260029608 ("queue: ensure io_uring_submit() returns the right error")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

src/queue.c

@@ -138,7 +138,7 @@ submit:
 	if (ret < 0)
 		return -errno;
 
-	return 0;
+	return ret;
 }
 
 /*