torture: Add --do-normal parameter to torture.sh help text

The --do-normal parameter was missing from the torture.sh script's help
text, so this commit adds it.  Hopefully better late than never!

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

Author: paulmckrcu

tools/testing/selftests/rcutorture/bin/torture.sh

@@ -94,6 +94,7 @@ usage () {
 	echo "       --do-kvfree / --do-no-kvfree / --no-kvfree"
 	echo "       --do-locktorture / --do-no-locktorture / --no-locktorture"
 	echo "       --do-none"
+	echo "       --do-normal / --do-no-normal / --no-normal"
 	echo "       --do-rcuscale / --do-no-rcuscale / --no-rcuscale"
 	echo "       --do-rcutasksflavors / --do-no-rcutasksflavors / --no-rcutasksflavors"
 	echo "       --do-rcutorture / --do-no-rcutorture / --no-rcutorture"