sound: Remove SND_DIAGNOSTIC section in buffer.c

The purpose of this has not been documented, but it seems like it makes
it possible to view the maximum number of bytes that passed to
sndbuf_feed(), as well as the maximum number of cycles taken inside its
main loop. These do not seem particularly useful anymore.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D55989

sys/dev/sound/pcm/buffer.c

@@ -506,29 +506,11 @@ sndbuf_dispose(struct snd_dbuf *b, u_int8_t *to, unsigned int count)
 	return 0;
 }
 
-#ifdef SND_DIAGNOSTIC
-static uint32_t snd_feeder_maxfeed = 0;
-SYSCTL_UINT(_hw_snd, OID_AUTO, feeder_maxfeed, CTLFLAG_RD,
-    &snd_feeder_maxfeed, 0, "maximum feeder count request");
-
-static uint32_t snd_feeder_maxcycle = 0;
-SYSCTL_UINT(_hw_snd, OID_AUTO, feeder_maxcycle, CTLFLAG_RD,
-    &snd_feeder_maxcycle, 0, "maximum feeder cycle");
-#endif
-
 /* count is number of bytes we want added to destination buffer */
 int
 sndbuf_feed(struct snd_dbuf *from, struct snd_dbuf *to, struct pcm_channel *channel, struct pcm_feeder *feeder, unsigned int count)
 {
 	unsigned int cnt, maxfeed;
-#ifdef SND_DIAGNOSTIC
-	unsigned int cycle;
-
-	if (count > snd_feeder_maxfeed)
-		snd_feeder_maxfeed = count;
-
-	cycle = 0;
-#endif
 
 	KASSERT(count > 0, ("can't feed 0 bytes"));
 
@@ -544,16 +526,8 @@ sndbuf_feed(struct snd_dbuf *from, struct snd_dbuf *to, struct pcm_channel *chan
 			break;
 		sndbuf_acquire(to, to->tmpbuf, cnt);
 		count -= cnt;
-#ifdef SND_DIAGNOSTIC
-		cycle++;
-#endif
 	} while (count != 0);
 
-#ifdef SND_DIAGNOSTIC
-	if (cycle > snd_feeder_maxcycle)
-		snd_feeder_maxcycle = cycle;
-#endif
-
 	return (0);
 }