ieee802154: mcr20a: simplify a bit 'mcr20a_handle_rx_read_buf_complete()'

Use a 'skb_put_data()' variant instead of rewritting it.
The __skb_put_data variant is safe here. It is obvious that the skb can
not overflow. It has just been allocated a few lines above with the same
'len'.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Xue Liu <liuxuenetmail@gmail.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

drivers/net/ieee802154/mcr20a.c

@@ -800,7 +800,7 @@ mcr20a_handle_rx_read_buf_complete(void *context)
 	if (!skb)
 		return;
 
-	memcpy(skb_put(skb, len), lp->rx_buf, len);
+	__skb_put_data(skb, lp->rx_buf, len);
 	ieee802154_rx_irqsafe(lp->hw, skb, lp->rx_lqi[0]);
 
 	print_hex_dump_debug("mcr20a rx: ", DUMP_PREFIX_OFFSET, 16, 1,