locktorture: Add kvm-recheck.sh plug-in for locktorture

This commit adds the kvm-recheck-lock.sh plug-in for locktorture to
print out lock-specific progress statistics.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>