iomap: fix comments in iomap_dio_rw

Double 'three' exists in the comments of iomap_dio_rw.
Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/iomap/direct-io.c

@@ -534,8 +534,8 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 
 	/*
 	 * We are about to drop our additional submission reference, which
-	 * might be the last reference to the dio.  There are three three
-	 * different ways we can progress here:
+	 * might be the last reference to the dio.  There are three different
+	 * ways we can progress here:
 	 *
 	 *  (a) If this is the last reference we will always complete and free
 	 *	the dio ourselves.