Replace NULL by 0 for parameters of type DWORD_PTR.

qwindowsaudiodeviceinfo.cpp: In member function 'bool QWindowsAudioDeviceInfo::testSettings(const QAudioFormat&) const':
qwindowsaudiodeviceinfo.cpp:220:50: warning: passing NULL to non-pointer argument 4 of 'MMRESULT waveOutOpen(LPHWAVEOUT, UINT, LPCWAVEFORMATEX, DWORD_PTR, DWORD_PTR, DWORD)' [-Wconversion-null]
                                 WAVE_FORMAT_QUERY) == MMSYSERR_NOERROR);                                                  ^
qwindowsaudiodeviceinfo.cpp:220:50: warning: passing NULL to non-pointer argument 5 of 'MMRESULT waveOutOpen(LPHWAVEOUT, UINT, LPCWAVEFORMATEX, DWORD_PTR, DWORD_PTR, DWORD)' [-Wconversion-null]
qwindowsaudiodeviceinfo.cpp:223:50: warning: passing NULL to non-pointer argument 4 of 'MMRESULT waveInOpen(LPHWAVEIN, UINT, LPCWAVEFORMATEX, DWORD_PTR, DWORD_PTR, DWORD)' [-Wconversion-null]
                                 WAVE_FORMAT_QUERY) == MMSYSERR_NOERROR);                                                  ^
qwindowsaudiodeviceinfo.cpp:223:50: warning: passing NULL to non-pointer argument 5 of 'MMRESULT waveInOpen(LPHWAVEIN, UINT, LPCWAVEFORMATEX, DWORD_PTR, DWORD_PTR, DWORD)' [-Wconversion-null]# ==[ Please wrap at 72 characters ]===================================|

Change-Id: Ie8f65e0e1f4f1274a1b634f3701ae0103e716d97
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>