serial: stm32: use port lock wrappers for break control

Commit 30e9458 ("serial: stm32: add support for break control")
added another usage of the port lock, but was merged on the same day as
c5d0666 ("serial: stm32: Use port lock wrappers"), therefore the
latter did not update this usage to use the port lock wrappers.

Fixes: c5d0666 ("serial: stm32: Use port lock wrappers")
Cc: stable <stable@kernel.org>
Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20241216145323.111612-1-ben.wolsieffer@hefring.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/stm32-usart.c

@@ -1051,14 +1051,14 @@ static void stm32_usart_break_ctl(struct uart_port *port, int break_state)
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	if (break_state)
 		stm32_usart_set_bits(port, ofs->rqr, USART_RQR_SBKRQ);
 	else
 		stm32_usart_clr_bits(port, ofs->rqr, USART_RQR_SBKRQ);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int stm32_usart_startup(struct uart_port *port)