greybus: audio: remove the unnecessary return statement

The return statement immediately after the BUG_ON of the gbcodec_write()
call is added by mistake. It's not causing any errors right now due to
that gbcodec_reg is currently not being used.

Testing Done:
- Audio playback on EVT2
Signed-off-by: David Lin <dtwlin@google.com>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/audio_codec.c

@@ -1099,7 +1099,6 @@ static int gbcodec_write(struct snd_soc_codec *codec, unsigned int reg,
 		return 0;
 
 	BUG_ON(reg >= GBCODEC_REG_COUNT);
-		return 0;
 
 	gbcodec_reg[reg] = value;
 	dev_dbg(codec->dev, "reg[%d] = 0x%x\n", reg, value);