ALSA: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200708203236.GA5112@embeddedor
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/azt3328.c b/sound/pci/azt3328.c
index 58167d84..77c7030 100644
--- a/sound/pci/azt3328.c
+++ b/sound/pci/azt3328.c
@@ -1232,7 +1232,7 @@ snd_azf3328_codec_setfmt(struct snd_azf3328_codec_data *codec,
 	case AZF_FREQ_32000: freq = SOUNDFORMAT_FREQ_32000; break;
 	default:
 		snd_printk(KERN_WARNING "unknown bitrate %d, assuming 44.1kHz!\n", bitrate);
-		/* fall-through */
+		fallthrough;
 	case AZF_FREQ_44100: freq = SOUNDFORMAT_FREQ_44100; break;
 	case AZF_FREQ_48000: freq = SOUNDFORMAT_FREQ_48000; break;
 	case AZF_FREQ_66200: freq = SOUNDFORMAT_FREQ_SUSPECTED_66200; break;