Missing argument warning in WP_MS_Themes_List_Table

[jeremyfelt]

The argument for $which was removed from the bulk_actions() call in [22376], causing a complaint by WP_MS_Themes_List_Table because it still expects to see this argument and pass it on. WP_List_Table does nothing with it anyway, so we're good to remove $which...

[jeremyfelt]

Removes unnecessary argument from bulk_actions()

[scribu]

Actually, the correct fix is to add back $which to both WP_List_Table and WP_Plugins_List_Table, since it does actually get passed in WP_List_Table::display_tablenav().

[nacin]

In 22395:

Remove methods that override but do nothing. props jeremyfelt for initial patch. fixes #22368.