Bug#773731: cache_check should be on root

[Timo Korvola]

Looks like the problem on system was not cache_check missing from the 
initrd, as I was not trying to cache root. The problem was cache_check 
missing from the actual root fs. vgchange -aay, executed after mounting 
root but before fsck, failed for the cached volumes. I suppose 
cache_check should be moved to /sbin. Maybe also the thin provisioning 
utilities if needed to fix #774560.

-- 
	Timo Korvola		<URL:http://www.iki.fi/tkorvola>