MAINTAINERS: Add Matthew Bobrowski as a reviewer

Matthew helps with fanotify already for some time and he'd like to do
more so let's add him as a reviewer.

CC: Matthew Bobrowski <repnop@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>

Author: jankara

MAINTAINERS

@@ -6938,6 +6938,7 @@ F:	net/core/failover.c
 FANOTIFY
 M:	Jan Kara <jack@suse.cz>
 R:	Amir Goldstein <amir73il@gmail.com>
+R:	Matthew Bobrowski <repnop@google.com>
 L:	linux-fsdevel@vger.kernel.org
 S:	Maintained
 F:	fs/notify/fanotify/