PHP 5.0 to 5.2 apparently did not support dynamic access
of static members, e.g. $classname::$method(). But support
for this was added in PHP 5.3. So there's no longer any
reason to use call_static_method().

Change-Id: Ib2c48251fb3e5a8ca4af9994bd2d648bc40794d2
behatneeded: Comment update only