aix: Removed unused local variable.

Found by Cppcheck.

src/audio/paudio/SDL_paudio.c

@@ -245,7 +245,6 @@ PAUDIO_OpenDevice(_THIS, void *handle, const char *devname, int iscapture)
     SDL_AudioFormat test_format;
     audio_init paud_init;
     audio_buffer paud_bufinfo;
-    audio_status paud_status;
     audio_control paud_control;
     audio_change paud_change;
     int fd = -1;