Added default case when converting format to pulse audio spec
Added default case when converting format to pulse audio spec

A sample size of 0 in QAudioFormat when converted to pulse audio format,
was not handled. The resulting format had the value PA_SAMPLE_U8 rather
than PA_SAMPLE_INVALID.

Task-number: MOBILITY-2029
Reviewed-by: Justin McPherson

tmcguire/qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,kaltsi/qt-mobility,KDE/android-qt-mobility,enthought/qt-mobility,qtproject/qt-mobility,qtproject/qt-mobility,qtproject/qt-mobility,kaltsi/qt-mobility,tmcguire/qt-mobility,KDE/android-qt-mobility,kaltsi/qt-mobility,enthought/qt-mobility,qtproject/qt-mobility,enthought/qt-mobility,tmcguire/qt-mobility,kaltsi/qt-mobility,KDE/android-qt-mobility,tmcguire/qt-mobility,KDE/android-qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,tmcguire/qt-mobility,enthought/qt-mobility,enthought/qt-mobility