RAID: Make RAID 4/5/6 display sync status under heading s/Copy%/Cpy%Sync

RAID:  Make RAID 4/5/6 display sync status under heading s/Copy%/Cpy%Sync

The heading 'Copy%' is specific to PVMOVE volumes, but can be generalized
to apply to LVM mirrors also.  It is a bit awkward to use 'Copy%' for
RAID 4/5/6, however - 'Sync%' would be more appropriate.  This is why
RAID 4/5/6 have not displayed their sync status by any means available to
'lvs' yet.

Example (old):
[root@hayes-02 lvm2]# lvs vg
  LV      VG   Attr      LSize  Pool Origin Data%  Move Log Cpy%Sy Convert
  lv    vg   -wi-a----  1.00g
  raid1 vg   rwi-a-r--  1.00g                             100.00
  raid4 vg   rwi-a-r--  1.01g
  raid5 vg   rwi-a-r--  1.01g
  raid6 vg   rwi-a-r--  1.01g

This patch changes the heading to 'Cpy%Sync' and allows RAID 4/5/6 to print
their sync percent in this field.

Example (new):
[root@hayes-02 lvm2]# lvs vg
  LV    VG   Attr      LSize Pool Origin Data%  Move Log Cpy%Sync Convert
  lv    vg   -wi-a---- 1.00g
  raid1 vg   rwi-a-r-- 1.00g                               100.00
  raid4 vg   rwi-a-r-- 1.01g                               100.00
  raid5 vg   rwi-a-r-- 1.01g                               100.00
  raid6 vg   rwi-a-r-- 1.01g                               100.00