As a part of the series to move xfs global stats from procfs to sysfs,
this patch consolidates the sysfs ops functions and removes redundancy.
Signed-off-by: NBill O'Donnell <billodo@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>