libsaria: Call add_alsa() during startup

Rather than resetting the preference, it's easier to call the add_alsa()
function if the preference is set.  This also cuts down on startup
warnings!

Signed-off-by: Bryan Schumaker <bjschuma@gmail.com>

libsaria/audio/alsa.cpp

@@ -88,7 +88,8 @@ namespace libsaria
 
 	void audio::init_alsa()
 	{
-		use_alsa(using_alsa());
+		if (using_alsa())
+			add_alsa();
 	}
 
 	void audio::quit_alsa()