[skin] fix notice error of "pukiwiki" & "xpwiki" on html side

スキン "pukiwiki" と "xpwiki" での Notice エラーの修正。（機能的な変更なし）

Author: nao-pon

html/modules/xpwiki/skin/pukiwiki/pukiwiki.skin.php

@@ -110,7 +110,7 @@
    <a href="<?php echo $link['reload']?>"><span class="small"><?php echo $link['reload']?></span></a>
  <?php } else if (!$is_top) {?>
    <span class="small">
-   <?php echo $this->do_plugin_inline('topicpath','',$_dum); ?>
+   <?php echo $this->do_plugin_inline('topicpath',''); ?>
    </span>
  <?php }?>
 <?php }?>

html/modules/xpwiki/skin/xpwiki/pukiwiki.skin.php

@@ -91,7 +91,7 @@
    <a href="<?php echo $link['reload'] ?>"><span class="small"><?php echo $link['reload'] ?></span></a>
  <?php } else if (!$is_top) { ?>
    <span class="small">
-   <?php echo $this->do_plugin_inline('topicpath','',$_dum); ?>
+   <?php echo $this->do_plugin_inline('topicpath',''); ?>
    </span>
  <?php } ?>
 <?php } ?>