7014796: Regression test java/awt/PrintJob/Text/stringwidth.sh cannot be terminated on Windows.

Reviewed-by: prr

test/java/awt/PrintJob/Text/StringWidth.java

@@ -63,7 +63,8 @@ public class StringWidth extends Frame {
   }
 
   public static void main(String[] args) {
-    new StringWidth();
+    StringWidth sw = new StringWidth();
+    sw.dispose();
   }
 
 }