Revert "serial: 8250: Let serial core initialise spin lock"

This reverts commit 679193b.

It appears that in QEmu the lock has been initialised differently
(it wasn't obvious on real hardware during testing). Let's
revert the change until the better approach will be developed.

Reported-by: kernel test robot <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: andy-shev

drivers/tty/serial/8250/8250_port.c

@@ -3194,6 +3194,7 @@ void serial8250_init_port(struct uart_8250_port *up)
 {
 	struct uart_port *port = &up->port;
 
+	spin_lock_init(&port->lock);
 	port->ops = &serial8250_pops;
 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);