audio effects: fix heap overflow

Check consistency of effect command reply sizes before
copying to reply address.

Also add null pointer check on reply size.
Also remove unused parameter warning.

Bug: 21953516.
Change-Id: I4cf00c12eaed696af28f3b7613f7e36f47a160c4
(cherry picked from commit 0f714a464d2425afe00d6450535e763131b40844)

int VirtualizerIsDeviceSupported(audio_devices_t deviceType) {
 switch (deviceType) {
 case AUDIO_DEVICE_OUT_WIRED_HEADSET:
 case AUDIO_DEVICE_OUT_WIRED_HEADPHONE:
 case AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_HEADPHONES:
 return 0;
 default :
 return -EINVAL;
 }
}

int VirtualizerIsDeviceSupported(audio_devices_t deviceType) {
 switch (deviceType) {
 case AUDIO_DEVICE_OUT_WIRED_HEADSET:
 case AUDIO_DEVICE_OUT_WIRED_HEADPHONE:
 case AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_HEADPHONES:
 return 0;
 default :
 return -EINVAL;
 }
}
