[PATCH] zd1201: Possible NULL dereference

If we enter the if(!zd) and set free to 1, we dereference zd in the exit
code.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/zd1201.c

@@ -193,10 +193,8 @@ static void zd1201_usbrx(struct urb *urb)
 	struct sk_buff *skb;
 	unsigned char type;
 
-	if (!zd) {
-		free = 1;
-		goto exit;
-	}
+	if (!zd)
+		return;
 
 	switch(urb->status) {
 		case -EILSEQ: