Cache inode get: Release lock after using it

Signed-off-by: Philippe DENIEL <philippe.deniel@cea.fr>
Fix bad worker index
Cleanup some NFSv2 remains

Signed-off-by: Amit Dror <amitd@infinidat.com>
Signed-off-by: Philippe DENIEL <philippe.deniel@cea.fr>
mount.9P helper is using "getent ahostv4" instead of "resolveip -s".
This breaks a dependance to mysql-server package.
cache_inode reap can deadlock with itself, release the lock before calling cih_remove_latched and get it again after it returned
cache_inode_key_delete should be usable multiple times on the same entry