coreaudio: remove useless log

There is one more complete just after.

modules/audio_output/coreaudio_common.c

@@ -741,8 +741,6 @@ MapOutputLayout(audio_output_t *p_aout, audio_sample_format_t *fmt,
     free(reslayout);
     aout_FormatPrepare(fmt);
 
-    msg_Dbg(p_aout, "selected %d physical channels for device output",
-            aout_FormatNbChannels(fmt));
     msg_Dbg(p_aout, "VLC will output: %s", aout_FormatPrintChannels(fmt));
 
     return VLC_SUCCESS;