dm unstripe: fix target length versus number of stripes size check
Since the unstripe target takes a target length which is the
size of *one* striped member we're trying to expose, not the
total size of *all* the striped members, the check does not
make sense and fails for some striped setups.
For example, say we have a 4TB striped device:
or
3907018496 sectors per underlying device:
if (sector_div(width, uc->stripes)) :
3907018496 / 2(num stripes) ==
1953509248
tmp_len = width;
if (sector_div(tmp_len, uc->chunk_size)) :
1953509248 / 256(chunk size) == 7630895.5
(fails)
Fix this by removing the first check which isn't valid for unstriping.
Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>