xfs_quota: modify commands which can't handle multiple types

xfs_quota: modify commands which can't handle multiple types

Some xfs_quota commands can't deal with multiple types together.
For example, if we run "limit -ug ...", one type will overwrite
the other. I find below commands can't handle multiple types:

  [quota, limit, timer, warn, dump, restore and quot]

(Although timer and warn command can't support -ugp types until
now, it will in one day.)

For every single $command, I change their ${command}_f function,
${command}_cmd structure and man page.

Signed-off-by: Zorro Lang <zlang@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>