Suppress overflow errors raised by Symbian DevSound during playback

Suppress overflow errors raised by Symbian DevSound during playback

When QAudioOutput::suspend() and QAudioOutput::resume() are called
repeatedly, with a short delay between each call, DevSound occasionally
raises a KErrOverflow error.  The backend previously translated this
into QAudio::IOError, causing the object to transition into the
QAudio::Stopped state.

This error can be safely ignored, with playback resuming as soon as
more audio data is provided to DevSound.  This patch therefore
suppresses the error.

Task-number: QTBUG-13059
Reviewed-by: Derick Hawcroft