Fixed problems in function that return None, and was not verified.
Fixed problems in function that return None, and was not verified.

Some functions with inject code didnot verify the result value before
convert to Shiboken types.

Fixes bug #998.

Reviewed by: Hugo Parente <hugo.lima@openbossa.org>
             Lauro Neto <lauro.neto@openbossa.org>

enthought/pyside,M4rtinK/pyside-bb10,RobinD42/pyside,M4rtinK/pyside-android,RobinD42/pyside,BadSingleton/pyside2,gbaty/pyside2,gbaty/pyside2,BadSingleton/pyside2,RobinD42/pyside,BadSingleton/pyside2,qtproject/pyside-pyside,IronManMark20/pyside2,enthought/pyside,enthought/pyside,M4rtinK/pyside-android,BadSingleton/pyside2,RobinD42/pyside,enthought/pyside,pankajp/pyside,M4rtinK/pyside-bb10,qtproject/pyside-pyside,M4rtinK/pyside-android,pankajp/pyside,RobinD42/pyside,gbaty/pyside2,enthought/pyside,RobinD42/pyside,IronManMark20/pyside2,PySide/PySide,M4rtinK/pyside-bb10,M4rtinK/pyside-android,IronManMark20/pyside2,qtproject/pyside-pyside,pankajp/pyside,enthought/pyside,IronManMark20/pyside2,RobinD42/pyside,M4rtinK/pyside-bb10,M4rtinK/pyside-bb10,M4rtinK/pyside-bb10,gbaty/pyside2,PySide/PySide,PySide/PySide,IronManMark20/pyside2,M4rtinK/pyside-android,qtproject/pyside-pyside,BadSingleton/pyside2,pankajp/pyside,PySide/PySide,enthought/pyside,qtproject/pyside-pyside,PySide/PySide,M4rtinK/pyside-android,pankajp/pyside,gbaty/pyside2