devmapper: allow devmapper devices as directlvm device
devmapper: allow devmapper devices as directlvm device

LVM allows creating a PV on top of an LV, but resolving symlinks
before checking the output of lvmdiskscan erroneously reports that an
LV is not an available device. It will resolve an LV's name into
/dev/dm-NN, which won't show up in lvmdiskscan.

Instead this patch looks for both names in lvmdiskscan.

Signed-off-by: Michael McCracken <af940a25c3809a29235b8e34c90fd6fdacecf6b2@cisco.com>

rhatdan/storage,containers/storage,rhatdan/storage,containers/storage,containers/storage,rhatdan/storage