torture: Avoid torture-test reboot loops

Currently, the various torture tests sometimes react to an early-boot
bug by rebooting.  This is almost always counterproductive, needlessly
consuming CPU time and bloating the console log.  This commit therefore
adds the "-no-reboot" argument to qemu so that reboot requests will
cause qemu to exit.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh

@@ -9,9 +9,10 @@
 #
 # Usage: kvm-test-1-run.sh config resdir seconds qemu-args boot_args_in
 #
-# qemu-args defaults to "-enable-kvm -nographic", along with arguments
-#			specifying the number of CPUs and other options
-#			generated from the underlying CPU architecture.
+# qemu-args defaults to "-enable-kvm -nographic -no-reboot", along with
+#			arguments specifying the number of CPUs and
+#			other options generated from the underlying
+#			CPU architecture.
 # boot_args_in defaults to value returned by the per_version_boot_params
 #			shell function.
 #
@@ -139,7 +140,7 @@ then
 fi
 
 # Generate -smp qemu argument.
-qemu_args="-enable-kvm -nographic $qemu_args"
+qemu_args="-enable-kvm -nographic -no-reboot $qemu_args"
 cpu_count=`configNR_CPUS.sh $resdir/ConfigFragment`
 cpu_count=`configfrag_boot_cpus "$boot_args_in" "$config_template" "$cpu_count"`
 if test "$cpu_count" -gt "$TORTURE_ALLOTED_CPUS"