[linux-lvm] merging snapshots and lvs bug

[ben]

Currently the first field of the attribute bits are set to 's' for a snapshot 
and 'S' for a merging snap. Unfortunatly 'S' was used for an invalid snapshot 
and lvs still uses it both ways. 

  LVM version:     2.02.86(2) (2011-07-08)
  Library version: 1.02.65 (2011-07-08)
  Driver version:  4.20.0