credential-cache, send_request: close fd when done

No need to keep it open any further.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

credential-cache.c

@@ -32,6 +32,7 @@ static int send_request(const char *socket, const struct strbuf *out)
 		write_or_die(1, in, r);
 		got_data = 1;
 	}
+	close(fd);
 	return got_data;
 }