drivers/net/wireless/ipw2x00: Use kmemdup

Use kmemdup when some other buffer is immediately copied into the
allocated region.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to,size,flag;
statement S;
@@

-  to = \(kmalloc\|kzalloc\)(size,flag);
+  to = kmemdup(from,size,flag);
   if (to==NULL || ...) S
-  memcpy(to, from, size);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ipw2x00/ipw2200.c

@@ -6624,13 +6624,12 @@ static int ipw_wx_set_genie(struct net_device *dev,
 		return -EINVAL;
 
 	if (wrqu->data.length) {
-		buf = kmalloc(wrqu->data.length, GFP_KERNEL);
+		buf = kmemdup(extra, wrqu->data.length, GFP_KERNEL);
 		if (buf == NULL) {
 			err = -ENOMEM;
 			goto out;
 		}
 
-		memcpy(buf, extra, wrqu->data.length);
 		kfree(ieee->wpa_ie);
 		ieee->wpa_ie = buf;
 		ieee->wpa_ie_len = wrqu->data.length;