Add "xstat" itself to the xstat optspec usage message.
Add "xstat" itself to the xstat optspec usage message.

Thanks to Jean-Baptiste <jbd@jbdenis.net> for pointing it out.

Signed-off-by: Rob Browning <1dc5917c2adeeba13d1ef33dbb40691a1b67cc65@defaultvalue.org>

mhoeher/bup,pombredanne/bup,apenwarr/bup,gevaerts/bup,mhoeher/bup,ToxicFrog/bup,apenwarr/bup,apenwarr/bup,pombredanne/bup,tjanez/bup,jbaber/bup,pombredanne/bup,tjanez/bup,ToxicFrog/bup,jbaber/bup,tjanez/bup,gevaerts/bup,ToxicFrog/bup,ToxicFrog/bup,mhoeher/bup,gevaerts/bup,jbaber/bup,ToxicFrog/bup,tjanez/bup,apenwarr/bup,gevaerts/bup,mhoeher/bup,mhoeher/bup,jbaber/bup,tjanez/bup,jbaber/bup,tjanez/bup,pombredanne/bup,mhoeher/bup,jbaber/bup,pombredanne/bup,pombredanne/bup,gevaerts/bup