[PATCH] ALSA: pcm: oss: Remove superfluous WARN_ON() for mulaw sanity check

[Takashi Iwai]

The PCM OSS mulaw plugin has a check of the format of the counter part
whether it's a linear format.  The check is with snd_BUG_ON() that
emits WARN_ON() when the debug config is set, and it confuses
syzkaller as if it were a serious issue.  Let's drop snd_BUG_ON() for
avoiding that.

While we're at it, correct the error code to a more suitable, EINVAL.

Reported-by: syzbot+23b22dc2e0b81cbfcc95 at syzkaller.appspotmail.com
Cc: <stable at vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/core/oss/mulaw.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/core/oss/mulaw.c b/sound/core/oss/mulaw.c
index 3788906421a7..fe27034f2846 100644
--- a/sound/core/oss/mulaw.c
+++ b/sound/core/oss/mulaw.c
@@ -329,8 +329,8 @@ int snd_pcm_plugin_build_mulaw(struct snd_pcm_substream *plug,
 		snd_BUG();
 		return -EINVAL;
 	}
-	if (snd_BUG_ON(!snd_pcm_format_linear(format->format)))
-		return -ENXIO;
+	if (!snd_pcm_format_linear(format->format))
+		return -EINVAL;
 
 	err = snd_pcm_plugin_build(plug, "Mu-Law<->linear conversion",
 				   src_format, dst_format,
-- 
2.16.4