[PATCH] remove redundant NULL checks before kfree() in sound/ and avoid casting pointers about to be kfree()'ed

Checking a pointer for NULL before calling kfree() on it is redundant,
kfree() deals with NULL pointers just fine.
This patch removes such checks from sound/

This patch also makes another, but closely related, change.
It avoids casting pointers about to be kfree()'ed.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/sound/oss/ad1889.c b/sound/oss/ad1889.c
index b767c62..2cfd214 100644
--- a/sound/oss/ad1889.c
+++ b/sound/oss/ad1889.c
@@ -277,8 +277,7 @@
 
 	for (j = 0; j < AD_MAX_STATES; j++) {
 		dmabuf = &dev->state[j].dmabuf;
-		if (dmabuf->rawbuf != NULL) 
-			kfree(dmabuf->rawbuf);
+		kfree(dmabuf->rawbuf);
 	}
 
 	kfree(dev);