MAINTAINERS: add Chandan Babu as XFS release manager

MAINTAINERS: add Chandan Babu as XFS release manager

I nominate Chandan Babu to take over release management for the upstream
kernel's XFS code.  He has had sufficient experience merging backports
to the 5.4 LTS tree, testing them, and sending them on to the LTS leads.

NOTE: I am /not/ nominating Chandan to take on any of the other roles I
have just dropped.  Bug triager, testing lead, and community manager are
open positions that need to be filled.  There's also maintainer for
supported LTS releases (4.14, 4.19, 5.10...).

Cc: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Carlos Maiolino <cem@kernel.org>