xfs: widen quota block counters to 64-bit integers

Widen the incore quota transaction delta structure to treat block
counters as 64-bit integers.  This is a necessary addition so that we
can widen the i_delayed_blks counter to be a 64-bit integer.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>