[SK_BUFF]: Introduce skb_copy_from_linear_data{_offset}

To clearly state the intent of copying from linear sk_buffs, _offset being a
overly long variant but interesting for the sake of saving some bytes.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/drivers/net/wan/lmc/lmc_main.c b/drivers/net/wan/lmc/lmc_main.c
index a576113..ae132c1 100644
--- a/drivers/net/wan/lmc/lmc_main.c
+++ b/drivers/net/wan/lmc/lmc_main.c
@@ -1702,7 +1702,7 @@
             if(!nsb) {
                 goto give_it_anyways;
             }
-            memcpy(skb_put(nsb, len), skb->data, len);
+            skb_copy_from_linear_data(skb, skb_put(nsb, len), len);
             
             nsb->protocol = lmc_proto_type(sc, skb);
             skb_reset_mac_header(nsb);