dcb: use nlmsg_free() instead of kfree()

These sk_buff structs were allocated with nlmsg_new() so they should
be freed with nlmsg_free().

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index e954d4c..fc56e85 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -1329,7 +1329,7 @@
 
 	nlh = nlmsg_put(skb, pid, 0, event, sizeof(*dcb), 0);
 	if (nlh == NULL) {
-		kfree(skb);
+		nlmsg_free(skb);
 		return -EMSGSIZE;
 	}
 
@@ -1434,7 +1434,7 @@
 
 	nlh = nlmsg_put(skb, pid, seq, RTM_GETDCB, sizeof(*dcb), flags);
 	if (nlh == NULL) {
-		kfree(skb);
+		nlmsg_free(skb);
 		return -EMSGSIZE;
 	}