serial: 8250: moxa: Store num_ports in brd

When struct moxa8250_board is allocated, then num_ports should
be initialized in order to use it later in moxa8250_remove.

Signed-off-by: Matwey V. Kornilov <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/8250/8250_moxa.c

···
 			   sizeof(unsigned int) * nr_ports, GFP_KERNEL);
 	if (!brd)
 		return -ENOMEM;
+	brd->num_ports = nr_ports;
 
 	memset(&uart, 0, sizeof(struct uart_8250_port));