net: core: use helper skb_ensure_writable in more places

Use helper skb_ensure_writable in two more places to simplify the code.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -3165,12 +3165,9 @@ int skb_checksum_help(struct sk_buff *skb)
 	offset += skb->csum_offset;
 	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
 
-	if (skb_cloned(skb) &&
-	    !skb_clone_writable(skb, offset + sizeof(__sum16))) {
-		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
-		if (ret)
-			goto out;
-	}
+	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
+	if (ret)
+		goto out;
 
 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
 out_set_summed:
@@ -3205,12 +3202,11 @@ int skb_crc32c_csum_help(struct sk_buff *skb)
 		ret = -EINVAL;
 		goto out;
 	}
-	if (skb_cloned(skb) &&
-	    !skb_clone_writable(skb, offset + sizeof(__le32))) {
-		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
-		if (ret)
-			goto out;
-	}
+
+	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
+	if (ret)
+		goto out;
+
 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
 						  skb->len - start, ~(__u32)0,
 						  crc32c_csum_stub));