rcutorture: Test summary at end of run with less chattiness

The commit causes kvm.sh to invoke kvm-recheck.sh at the end of each
run, and causes kvm-recheck.sh to print only the name of the test, not
the full path to the corresponding Kconfig file.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Greg KH <gregkh@linuxfoundation.org>