DQALLOC is only ever used with xfs_qm_dqget*, and the only flag that the
_dqget family of functions cares about is DQALLOC.  Therefore, change
it to a boolean 'can alloc?' flag for the dqget interfaces where that
makes sense.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>