ovl: add Amir as co-maintainer

Amir has implemented lots of features in overlayfs and is very active in
maintenance.

Make this official in the MAINTAINERS file.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

MAINTAINERS

diff --git a/MAINTAINERS b/MAINTAINERS
index f794002..e0b2cfa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15846,6 +15846,7 @@
 
 OVERLAY FILESYSTEM
 M:	Miklos Szeredi <miklos@szeredi.hu>
+M:	Amir Goldstein <amir73il@gmail.com>
 L:	linux-unionfs@vger.kernel.org
 S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git