rcutorture: Abstract kvm-recheck.sh

This commit creates a plug-in to allow kvm-recheck.sh to process
non-rcutorture console output.

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

diff --cc tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh
Simple merge

diff --cc tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
Simple merge