MAINTAINERS: SGI no longer maintaining XFS

SGI is stepping out of maintainer roles for xfs, xfsprogs, xfsdump, and
xfstests.  This removes me from the MAINTAINERS entry.
Signed-off-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

MAINTAINERS

@@ -9715,7 +9715,6 @@ F:	drivers/xen/*swiotlb*
 XFS FILESYSTEM
 P:	Silicon Graphics Inc
 M:	Dave Chinner <david@fromorbit.com>
-M:	Ben Myers <bpm@sgi.com>
 M:	xfs@oss.sgi.com
 L:	xfs@oss.sgi.com
 W:	http://oss.sgi.com/projects/xfs