src/queue: clean _io_uring_get_cqe() err handling

Doesn't change behaviour, just a little cleanup.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/src/queue.c b/src/queue.c
index dd1df2a..be461c6 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -117,8 +117,11 @@
 					data->sz);
 		if (ret < 0) {
 			err = -errno;
-		} else if (ret == (int)data->submit) {
-			data->submit = 0;
+			break;
+		}
+
+		data->submit -= ret;
+		if (ret == (int)data->submit) {
 			/*
 			 * When SETUP_IOPOLL is set, __sys_io_uring enter()
 			 * must be called to reap new completions but the call
@@ -127,12 +130,10 @@
 			 */
 			if (!(ring->flags & IORING_SETUP_IOPOLL))
 				data->wait_nr = 0;
-		} else {
-			data->submit -= ret;
 		}
 		if (cqe)
 			break;
-	} while (!err);
+	} while (1);
 
 	*cqe_ptr = cqe;
 	return err;