MAINTAINERS: add a co-maintainer from samsung for F2FS

This patch adds a samsung guy for an F2FS maintainer.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

MAINTAINERS

@@ -3775,6 +3775,7 @@ F:	include/linux/fscache*.h
 
 F2FS FILE SYSTEM
 M:	Jaegeuk Kim <jaegeuk@kernel.org>
+M:	Changman Lee <cm224.lee@samsung.com>
 L:	linux-f2fs-devel@lists.sourceforge.net
 W:	http://en.wikipedia.org/wiki/F2FS
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git