xfs/007: use gquotino for project quotas on pre-v5 superblocks

xfs/007: use gquotino for project quotas on pre-v5 superblocks

This test checks block usage on quota inodes based on the inode number
values stored in the superblock. Version 5 superblocks (crc=1) have an
independent project quota inode field to support concurrent group and
project quotas. Older superblocks do not have the pquotino field. The
gquotino field is reused for project quotas.

The test currently unconditionally uses the pquotino field to determine
the project quota inode. This causes failures on pre-v5 superblocks as
the test queries the block usage of an incorrect inode number. Update
the test to use gquotino as the project quota inode on such filesystems.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>