Fix __extend_pgfrags function.

We should adjust count of skb fragments even if
`tail_frags` is equal to zero.
Also remove unnecessary linear transformation
during making frames.

fw/http_frame.c

@@ -1932,14 +1932,6 @@ tfw_h2_insert_frame_header(struct sock *sk, TfwH2Ctx *ctx, TfwStream *stream,
 	char *data;
 	int r;
 
-	if (unlikely(type == HTTP2_DATA
-		     && skb_headlen(stream->xmit.skb_head)))
-	{
-		if ((r = tfw_http_msg_linear_transform(&it)))
-			return r;
-		stream->xmit.skb_head = it.skb_head;
-	}
-
 	data = ss_skb_data_ptr_by_offset(stream->xmit.skb_head,
 					 stream->xmit.frame_length);
 	if(unlikely(!data))

fw/ss_skb.c

@@ -231,7 +231,7 @@ __extend_pgfrags(struct sk_buff *skb_head, struct sk_buff *skb, int from, int n)
 
 		/* No fragments to shift. */
 		if (!tail_frags)
-			return 0;
+			goto finish;
 
 		/*
 		 * Move @n_excess number of page fragments to new SKB. We
@@ -262,6 +262,8 @@ __extend_pgfrags(struct sk_buff *skb_head, struct sk_buff *skb, int from, int n)
 	if (n_shift > 0)
 		memmove(&si->frags[from + n],
 			&si->frags[from], n_shift * sizeof(skb_frag_t));
+
+finish:
 	si->nr_frags += n - n_excess;
 
 	return 0;