torture: Add kvm-series.sh to test commit/scenario combination

torture: Add kvm-series.sh to test commit/scenario combination

This commit adds a kvm-series.sh script that takes a list of scenarios and
a list of commits, and then runs each scenario on all of the commits.
A given scenario is run on all the commits before advancing to the
next scenario to minimize build times.  The successes and failures are
summarized at the end of the run.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>