Make Q_QUOTAON / Q_QUOTAOFF quotactl call ->quota_enable /
->quota_disable callback when provided. To match current behavior of
ocfs2 & ext4 we make these quotactls turn on / off quota enforcement for
appropriate quota type.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>