staging/lustre/ldlm: Remove posix lock (flock) deadlock detection

This is server-side code that cannot work on the client
(vfs would do this check on the local node).

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>