drivers: serial: ra_sci: revise switch-case in callback_adapter

Unified switch-case usage in `uart_ra_sci_callback_adapter` to use
`break` instead of `return`.
Typically, a `break` is used in switch-case statements unless an early
return is necessary, in which case `return` is appropriate.

For this case, using a `break` statement is the more suitable choice.

Signed-off-by: Pisit Sawangvonganan <[email protected]>

Author: ndrs-pst

drivers/serial/uart_renesas_ra_sci.c

@@ -860,17 +860,22 @@ static void uart_ra_sci_callback_adapter(struct st_uart_callback_arg *fsp_args)
 
 	switch (fsp_args->event) {
 	case UART_EVENT_TX_COMPLETE:
-		return async_evt_tx_done(dev);
+		async_evt_tx_done(dev);
+		break;
 	case UART_EVENT_RX_COMPLETE:
 		async_evt_rx_complete(dev);
 	case UART_EVENT_ERR_PARITY:
-		return async_evt_rx_err(dev, UART_ERROR_PARITY);
+		async_evt_rx_err(dev, UART_ERROR_PARITY);
+		break;
 	case UART_EVENT_ERR_FRAMING:
-		return async_evt_rx_err(dev, UART_ERROR_FRAMING);
+		async_evt_rx_err(dev, UART_ERROR_FRAMING);
+		break;
 	case UART_EVENT_ERR_OVERFLOW:
-		return async_evt_rx_err(dev, UART_ERROR_OVERRUN);
+		async_evt_rx_err(dev, UART_ERROR_OVERRUN);
+		break;
 	case UART_EVENT_BREAK_DETECT:
-		return async_evt_rx_err(dev, UART_BREAK);
+		async_evt_rx_err(dev, UART_BREAK);
+		break;
 	case UART_EVENT_TX_DATA_EMPTY:
 	case UART_EVENT_RX_CHAR:
 		break;