audio_wrapper: fix errorhandling and function-visibility

Change-Id: I14e5fbe29a39c83684fe78bdc59fd7aaff3b3c33
motoaudiocompat: inject symbols needed by motorola-blob

as audio.primary.omap4.so depend on a symbol no longer present in libmedia
(_ZN7android11AudioSystem24getDeviceConnectionStateE15audio_devices_tPKc),
this symbol is now injected into libasound, which is used by the blob
audio.primary.omap4.so.

Change-Id: I999959f7b42e51f813cd987d27bf45c8b1bb2724