rcutorture/kvm.sh: Use consistent help text for --qemu-args

The '--qemu-args' option's help text is wrongly copied from '--qemu-cmd'
option and its argument type description message format is inconsistent
with other arguments.  This commit fixes the usage and type messages to
be consistent with others.

Fixes: e9ce6400 ("rcutorture: Add --qemu-args argument to kvm.sh")
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

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

@@ -70,7 +70,7 @@ usage () {
 	echo "       --kmake-arg kernel-make-arguments"
 	echo "       --mac nn:nn:nn:nn:nn:nn"
 	echo "       --no-initrd"
-	echo "       --qemu-args qemu-system-..."
+	echo "       --qemu-args qemu-arguments"
 	echo "       --qemu-cmd qemu-system-..."
 	echo "       --results absolute-pathname"
 	echo "       --torture rcu"
@@ -150,7 +150,7 @@ do
 		TORTURE_INITRD=""; export TORTURE_INITRD
 		;;
 	--qemu-args|--qemu-arg)
-		checkarg --qemu-args "-qemu args" $# "$2" '^-' '^error'
+		checkarg --qemu-args "(qemu arguments)" $# "$2" '^-' '^error'
 		TORTURE_QEMU_ARG="$2"
 		shift
 		;;