net: macsec: use skb_ensure_writable_head_tail to expand the skb

Use skb_ensure_writable_head_tail to expand the skb if needed instead of
reimplementing a similar operation.

Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Radu Pirea (NXP OSS)

drivers/net/macsec.c

@@ -604,26 +604,11 @@ static struct sk_buff *macsec_encrypt(struct sk_buff *skb,
 		return ERR_PTR(-EINVAL);
 	}
 
-	if (unlikely(skb_headroom(skb) < MACSEC_NEEDED_HEADROOM ||
-		     skb_tailroom(skb) < MACSEC_NEEDED_TAILROOM)) {
-		struct sk_buff *nskb = skb_copy_expand(skb,
-						       MACSEC_NEEDED_HEADROOM,
-						       MACSEC_NEEDED_TAILROOM,
-						       GFP_ATOMIC);
-		if (likely(nskb)) {
-			consume_skb(skb);
-			skb = nskb;
-		} else {
-			macsec_txsa_put(tx_sa);
-			kfree_skb(skb);
-			return ERR_PTR(-ENOMEM);
-		}
-	} else {
-		skb = skb_unshare(skb, GFP_ATOMIC);
-		if (!skb) {
-			macsec_txsa_put(tx_sa);
-			return ERR_PTR(-ENOMEM);
-		}
+	ret = skb_ensure_writable_head_tail(skb, dev);
+	if (unlikely(ret < 0)) {
+		macsec_txsa_put(tx_sa);
+		kfree_skb(skb);
+		return ERR_PTR(ret);
 	}
 
 	unprotected_len = skb->len;