mxser: simplify FCR computation in mxser_change_speed()

Provided FIFO is always enabled for MUST chips, move its FCR setting out
of PORT_8250/PORT_16450 special case in mxser_change_speed(). Now, we
can pre-set fcr to zero and invert the condition of the 'if'.

This makes the code more readable (no functional change intended).

Signed-off-by: Jiri Slaby <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/mxser.c

···
 	if (cflag & CMSPAR)
 		cval |= UART_LCR_SPAR;
 
-	if ((info->type == PORT_8250) || (info->type == PORT_16450)) {
-		if (info->board->must_hwid) {
-			fcr = UART_FCR_ENABLE_FIFO;
-			fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
-			mxser_set_must_fifo_value(info);
-		} else
-			fcr = 0;
-	} else {
-		fcr = UART_FCR_ENABLE_FIFO;
-		if (info->board->must_hwid) {
-			fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
-			mxser_set_must_fifo_value(info);
-		} else {
-			switch (info->rx_high_water) {
-			case 1:
-				fcr |= UART_FCR_TRIGGER_1;
-				break;
-			case 4:
-				fcr |= UART_FCR_TRIGGER_4;
-				break;
-			case 8:
-				fcr |= UART_FCR_TRIGGER_8;
-				break;
-			default:
-				fcr |= UART_FCR_TRIGGER_14;
-				break;
-			}
+	fcr = 0;
+	if (info->board->must_hwid) {
+		fcr |= UART_FCR_ENABLE_FIFO |
+			MOXA_MUST_FCR_GDA_MODE_ENABLE;
+		mxser_set_must_fifo_value(info);
+	} else if (info->type != PORT_8250 && info->type != PORT_16450) {
+		fcr |= UART_FCR_ENABLE_FIFO;
+		switch (info->rx_high_water) {
+		case 1:
+			fcr |= UART_FCR_TRIGGER_1;
+			break;
+		case 4:
+			fcr |= UART_FCR_TRIGGER_4;
+			break;
+		case 8:
+			fcr |= UART_FCR_TRIGGER_8;
+			break;
+		default:
+			fcr |= UART_FCR_TRIGGER_14;
+			break;
 		}
 	}