Fix typo in comment

Author: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://www.postgresql.org/message-id/CABPTF7V8CbOXGePqrad6EH3Om7DRhNiO3C0rQ-62UuT7RdU-GQ@mail.gmail.com

src/backend/storage/aio/read_stream.c

@@ -283,7 +283,7 @@ read_stream_start_pending_read(ReadStream *stream)
 			/*
 			 * Sequential:  Issue advice until the preadv() calls have caught
 			 * up with the first advice issued for this sequential region, and
-			 * then stay of the way of the kernel's own read-ahead.
+			 * then stay out of the way of the kernel's own read-ahead.
 			 */
 			if (stream->seq_until_processed != InvalidBlockNumber)
 				flags |= READ_BUFFERS_ISSUE_ADVICE;