`wp_xmlrpc_server::wp_getPage()` should `return new IXR_Error(` instead of `return(new IXR_Error(`. One of the few places that is unparseable by static analysis.

See #27882.


git-svn-id: https://develop.svn.wordpress.org/trunk@28636 602fd350-edb4-49c9-b593-d223f7449a82