xfs/007: check correct quota inodes

xfs/007: check correct quota inodes

Commit b8cac56 ("xfs/007: add project quota Q_XQUOTARM test") has
been broken since it was added - the new code checked the group
quota inode rather than the project quota inode and so always
reported a pre-RM block count of zero.  This occurred due to a copy
and paste of the existing user/group test code and didn't fix up all
the code properly.

Factor the common code into a single function, and pass in the
correct variables the tests require. While there, make sure that we
remove the 007.full file before the test starts to aid future
debugging and also check that project quotas are supported before
trying to test them.

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