7107020: java.net.PlainSocketImpl.socketSetOption() calls itself

Reviewed-by: alanb, chegar
Contributed-by: kurchi.subhra.hazra@oracle.com

src/windows/classes/java/net/PlainSocketImpl.java

@@ -314,7 +314,7 @@ class PlainSocketImpl extends AbstractPlainSocketImpl
 
     void socketSetOption(int cmd, boolean on, Object value)
         throws SocketException {
-        socketSetOption(cmd, on, value);
+        impl.socketSetOption(cmd, on, value);
     }
 
     int socketGetOption(int opt, Object iaContainerObj) throws SocketException {