drivers/net/cxgb3: Use memdup_user

Use memdup_user when user data is immediately copied into the
allocated region.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to,size,flag;
position p;
identifier l1,l2;
@@

-  to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+  to = memdup_user(from,size);
   if (
-      to==NULL
+      IS_ERR(to)
                 || ...) {
   <+... when != goto l1;
-  -ENOMEM
+  PTR_ERR(to)
   ...+>
   }
-  if (copy_from_user(to, from, size) != 0) {
-    <+... when != goto l2;
-    -EFAULT
-    ...+>
-  }
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/cxgb3/cxgb3_main.c

@@ -2311,15 +2311,9 @@ static int cxgb_extension_ioctl(struct net_device *dev, void __user *useraddr)
 		if (copy_from_user(&t, useraddr, sizeof(t)))
 			return -EFAULT;
 		/* Check t.len sanity ? */
-		fw_data = kmalloc(t.len, GFP_KERNEL);
-		if (!fw_data)
-			return -ENOMEM;
-
-		if (copy_from_user
-			(fw_data, useraddr + sizeof(t), t.len)) {
-			kfree(fw_data);
-			return -EFAULT;
-		}
+		fw_data = memdup_user(useraddr + sizeof(t), t.len);
+		if (IS_ERR(fw_data))
+			return PTR_ERR(fw_data);
 
 		ret = t3_load_fw(adapter, fw_data, t.len);
 		kfree(fw_data);