MAINTAINERS: update IOMAP FILESYSTEM LIBRARY and XFS FILESYSTEM

In IOMAP FILESYSTEM LIBRARY and XFS FILESYSTEM, the M(ail): entry is
redundant with the L(ist): entry, remove the redundant M(ail): entry.
Signed-off-by: NTiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

MAINTAINERS

@@ -10238,8 +10238,6 @@ F:	drivers/net/ethernet/sgi/ioc3-eth.c
 IOMAP FILESYSTEM LIBRARY
 M:	Christoph Hellwig <hch@infradead.org>
 M:	Darrick J. Wong <djwong@kernel.org>
-M:	linux-xfs@vger.kernel.org
-M:	linux-fsdevel@vger.kernel.org
 L:	linux-xfs@vger.kernel.org
 L:	linux-fsdevel@vger.kernel.org
 S:	Supported
@@ -21596,7 +21594,6 @@ F:	drivers/xen/*swiotlb*
 XFS FILESYSTEM
 C:	irc://irc.oftc.net/xfs
 M:	Darrick J. Wong <djwong@kernel.org>
-M:	linux-xfs@vger.kernel.org
 L:	linux-xfs@vger.kernel.org
 S:	Supported
 W:	http://xfs.org/