xfs_quota: remove extra 30 seconds from time limit reporting

xfs_quota: remove extra 30 seconds from time limit reporting

The addition of 30s makes little sense; it's only added to the
values reported via the userspace tool, and doesn't reflect the
actual values used in the kernel. Setting a time limit to
"00:30:00" and reporting back "00:30:30" makes little sense to me.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>