io_uring: fix a typo in a comment

thatn -> than.

Signed-off-by: Liming Wu <19092205@suning.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -145,7 +145,7 @@ struct io_rings {
 	/*
 	 * Number of completion events lost because the queue was full;
 	 * this should be avoided by the application by making sure
-	 * there are not more requests pending thatn there is space in
+	 * there are not more requests pending than there is space in
 	 * the completion queue.
 	 *
 	 * Written by the kernel, shouldn't be modified by the