Use integer_to_binary when possible

src/cowboy_http.erl

@@ -862,7 +862,7 @@ commands(State=#state{socket=Socket, transport=Transport, streams=Streams}, Stre
 	case lists:keyfind(StreamID, #stream.id, Streams) of
 		#stream{version='HTTP/1.1'} ->
 			Size = iolist_size(Data),
-			Transport:send(Socket, [integer_to_list(Size, 16), <<"\r\n">>, Data, <<"\r\n">>]);
+			Transport:send(Socket, [integer_to_binary(Size, 16), <<"\r\n">>, Data, <<"\r\n">>]);
 		#stream{version='HTTP/1.0'} ->
 			Transport:send(Socket, Data)
 	end,

test/http_SUITE.erl

@@ -945,7 +945,7 @@ do_body_to_chunks(ChunkSize, Body, Acc) ->
 		false -> ChunkSize
 	end,
 	<< Chunk:ChunkSize2/binary, Rest/binary >> = Body,
-	ChunkSizeBin = list_to_binary(integer_to_list(ChunkSize2, 16)),
+	ChunkSizeBin = integer_to_binary(ChunkSize2, 16),
 	do_body_to_chunks(ChunkSize, Rest,
 		[<< ChunkSizeBin/binary, "\r\n", Chunk/binary, "\r\n" >>|Acc]).