tools/memory-model: Add "--" to parseargs.sh for additional arguments

Currently, parseargs.sh expects to consume all the command-line arguments,
which prevents the calling script from having any of its own arguments.
This commit therefore causes parseargs.sh to stop consuming arguments
when it encounters a "--" argument, leaving any remaining arguments for
the calling script.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/memory-model/scripts/parseargs.sh

@@ -83,7 +83,7 @@ do
 			echo "Cannot create directory --destdir '$LKMM_DESTDIR'"
 			usage
 		fi
-		if test -d "$LKMM_DESTDIR" -a -w "$LKMM_DESTDIR" -a -x "$LKMM_DESTDIR"
+		if test -d "$LKMM_DESTDIR" -a -x "$LKMM_DESTDIR"
 		then
 			:
 		else
@@ -127,6 +127,10 @@ do
 		LKMM_TIMEOUT="$2"
 		shift
 		;;
+	--)
+		shift
+		break
+		;;
 	*)
 		echo Unknown argument $1
 		usage