sideband.c: make send_sideband() return void

The send_sideband() function uses write_or_die() for writing data which
immediately terminates the process on errors. If no such error occurred,
send_sideband() always returned the value that was passed as fourth
parameter prior to this commit. This value is already known to the
caller in any case, so let's turn send_sideband() into a void function
instead.

Signed-off-by: Lukas Fleischer <lfleischer@lfos.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/upload-pack.c b/upload-pack.c
index f19444d..f9d6410 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -60,8 +60,10 @@
 
 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
 {
-	if (use_sideband)
-		return send_sideband(1, fd, data, sz, use_sideband);
+	if (use_sideband) {
+		send_sideband(1, fd, data, sz, use_sideband);
+		return sz;
+	}
 	if (fd == 3)
 		/* emergency quit */
 		fd = 2;