[PATCH] Fix sb_mixer use before validation

dev should be validated before it is being used as index to array.

Coverity bug #871
Signed-off-by: Eugene Teo <eugene.teo@eugeneteo.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

sound/oss/sb_mixer.c

@@ -273,14 +273,14 @@ int sb_common_mixer_set(sb_devc * devc, int dev, int left, int right)
 	int regoffs;
 	unsigned char val;
 
+	if ((dev < 0) || (dev >= devc->iomap_sz))
+		return -EINVAL;
+
 	regoffs = (*devc->iomap)[dev][LEFT_CHN].regno;
 
 	if (regoffs == 0)
 		return -EINVAL;
 
-	if ((dev < 0) || (dev >= devc->iomap_sz))
-	    return -EINVAL;
-
 	val = sb_getmixer(devc, regoffs);
 	change_bits(devc, &val, dev, LEFT_CHN, left);