quota: Hook up Q_XSETQLIM for id 0 to ->set_info

Setting timers or warning counts for id 0 via Q_XSETQLIM is used to
actually set time limits and warning limits for all users. Hook up
->set_info to this so that VFS quota time limits get set the same
way as XFS ones.

When doing this Q_XSETQLIM for XFS is effectively split into two
independent transactions - one for setting timers and warning limits and
one for setting space and inode limits. Although this is inefficient, it
is rare enough that it does not matter.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>