ovl: update MAINTAINERS

There's a union/overlay specific mailing list now.  Also add a git tree.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/MAINTAINERS b/MAINTAINERS
index af1e738..0ff630d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6890,9 +6890,10 @@
 
 OVERLAY FILESYSTEM
 M:	Miklos Szeredi <miklos@szeredi.hu>
-L:	linux-fsdevel@vger.kernel.org
+L:	linux-unionfs@vger.kernel.org
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git
 S:	Supported
-F:	fs/overlayfs/*
+F:	fs/overlayfs/
 F:	Documentation/filesystems/overlayfs.txt
 
 P54 WIRELESS DRIVER