[XFS] Fix uquota and oquota enforcement problems.

When uquota and oquota (gquota/pquota) are enabled for accounting both are
enforced if ether has enforcement active.

Conditions:

- Both XFS_UQUOTA_ACCT and XFS_GQUOTA_ACCT are enabled.

- Either XFS_UQUOTA_ENFD or XFS_OQUOTA_ENFD is enabled.

- The usage without enforce is reached at the soft limit.

Problems:

1. "repquota" shows all grace time even if no enforcement.

2. we cannot make a file over a hard limits even if no enforcement.

SGI-PV: 962291
SGI-Modid: xfs-linux-melb:xfs-kern:28272a

Signed-off-by: Kouta Ooizumi <k-ooizumi@tnes.nec.co.jp>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>