Refresh device filters before full device rescan in lvmcache.

Refresh device filters before full device rescan in lvmcache.

The sysfs filter initialise hash of available devices using
scan of /sys/block. We need to refresh even this hash
when performing full scan otherwise the newly appeared
device could be rejected, because there is no entry
in sysfs filter.

This easily could happen when attaching new device
to cluster node. (Only force refresh of context
in clvmd -R works here now).

Unfortunately consequences of this are much worse,
missing device part on that node is replaced with missing segment
(even when no partial arg is selected) and this directly
lead to data corruption.

See https://bugzilla.redhat.com/show_bug.cgi?id=538515

Simply fix it by refreshing device filters in lvmcache
before performing the full device scan.