pkt-line.[ch]: remove unused packet_buf_write_len()

This function was added in f1f4d8acf4 (pkt-line: add
packet_buf_write_len function, 2018-03-15) for use in
0f1dc53f45 (remote-curl: implement stateless-connect command,
2018-03-15).

In a97d00799a (remote-curl: use post_rpc() for protocol v2 also,
2019-02-21) that only user of it went away, let's remove it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

pkt-line.c

@@ -252,22 +252,6 @@ void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 	va_end(args);
 }
 
-void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len)
-{
-	size_t orig_len, n;
-
-	orig_len = buf->len;
-	strbuf_addstr(buf, "0000");
-	strbuf_add(buf, data, len);
-	n = buf->len - orig_len;
-
-	if (n > LARGE_PACKET_MAX)
-		die(_("protocol error: impossibly long line"));
-
-	set_packet_header(&buf->buf[orig_len], n);
-	packet_trace(data, len, 1);
-}
-
 int write_packetized_from_fd_no_flush(int fd_in, int fd_out)
 {
 	char *buf = xmalloc(LARGE_PACKET_DATA_MAX);

pkt-line.h

@@ -29,7 +29,6 @@ void packet_buf_delim(struct strbuf *buf);
 void set_packet_header(char *buf, int size);
 void packet_write(int fd_out, const char *buf, size_t size);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
-void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len);
 int packet_flush_gently(int fd);
 int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 int write_packetized_from_fd_no_flush(int fd_in, int fd_out);