xfs_quota: fix report command parsing

xfs_quota: fix report command parsing

The report command line needs to be parsed as a whole not as
individual elements - report_f() is set up to do this correctly.
When treated as non-global command line, the report function is
called once for each command line arg, resulting in reports being
issued multiple times.

Set the command to be a global command so that it is only called
once.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Mark Tinguely <tinguely@sgi.com>