[DECNET]: Use kmemdup

Code diff stats:

[acme@newtoy net-2.6.20]$ codiff /tmp/decnet.ko.before /tmp/decnet.ko.after
/pub/scm/linux/kernel/git/acme/net-2.6.20/net/decnet/dn_dev.c:
  dn_dev_sysctl_register |  -51
 1 function changed, 51 bytes removed
[acme@newtoy net-2.6.20]$
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

net/decnet/dn_dev.c

@@ -255,12 +255,10 @@ static void dn_dev_sysctl_register(struct net_device *dev, struct dn_dev_parms *
 	struct dn_dev_sysctl_table *t;
 	int i;
 
-	t = kmalloc(sizeof(*t), GFP_KERNEL);
+	t = kmemdup(&dn_dev_sysctl, sizeof(*t), GFP_KERNEL);
 	if (t == NULL)
 		return;
 
-	memcpy(t, &dn_dev_sysctl, sizeof(*t));
-
 	for(i = 0; i < ARRAY_SIZE(t->dn_dev_vars) - 1; i++) {
 		long offset = (long)t->dn_dev_vars[i].data;
 		t->dn_dev_vars[i].data = ((char *)parms) + offset;