send-pack: clarify that cmds_sent is a boolean

We use it to make sure that the feature request is sent only once on
the very first request packet (ignoring the "shallow " line, which
was an unfortunate mistake we cannot retroactively fix with existing
receive-pack already deployed in the field) and we set it to "true"
with cmds_sent++, not because we care about the actual number of
updates sent but because it is merely an idiomatic way.

Set it explicitly to one to clarify that the code that uses this
variable only cares about its zero-ness.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

send-pack.c

@@ -304,15 +304,16 @@ int send_pack(struct send_pack_args *args,
 
 		old_hex = sha1_to_hex(ref->old_sha1);
 		new_hex = sha1_to_hex(ref->new_sha1);
-		if (!cmds_sent)
+		if (!cmds_sent) {
 			packet_buf_write(&req_buf,
 					 "%s %s %s%c%s",
 					 old_hex, new_hex, ref->name, 0,
 					 cap_buf.buf);
-		else
+			cmds_sent = 1;
+		} else {
 			packet_buf_write(&req_buf, "%s %s %s",
 					 old_hex, new_hex, ref->name);
-		cmds_sent++;
+		}
 	}
 
 	if (args->stateless_rpc) {