Removed useless $title parameter to InfoAction::pageInfo()

Removed useless $title parameter to InfoAction::pageInfo()

The $title variable is set to $this->getTitle() before its
first use in that method, so it's useless to pass it as parameter.

Also changed the call to exist() in InfoAction::onView() to use
the Page object instead of the Title object.

Change-Id: Ic07ee0ccccfd9cc3aabd497aebf7965136a2d3bd