xfs: shut down the filesystem if we screw up quota reservation

If we ever screw up the quota reservations enough to trip the
assertions, something's wrong with the quota code.  Shut down the
filesystem when this happens, because this is corruption.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>