rcutorture: Test both RCU-sched and RCU-bh for Tiny RCU

rcutorture: Test both RCU-sched and RCU-bh for Tiny RCU

Tiny RCU supports both RCU-sched and RCU-bh, but only RCU-sched is
currently tested by the rcutorture scripts.  This commit therefore
changes the TINY02 configuration to test RCU-bh, with TINY01 continuing
to test RCU-sched.

This shortcoming of the current rcutorture tests was located by mutation
testing by Iftekhar.  The idea behind mutation testing is to automatically
mutate the code under test.  If a given mutant is not caught by testing,
this is a hint that the testing might need to be improved, as was the
case here.  Note that this is only a hint because it is possible to mutate
the code into something else that still works.  For example, a mutation
that removes (say) a WARN_ON() will not normally result in a test failure.

This change resulted in the test failure caused by list mishandling,
which is fixed by the next commit.

Reported-by: "Ahmed, Iftekhar" <ahmedi@onid.oregonstate.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>