can: bittiming: can_get_bittiming(): use direct return and remove unneeded else

Clean up the code flow a bit, don't assign err variable but directly
return. Remove the unneeded else, too.

Link: https://lore.kernel.org/all/20230202110854.2318594-5-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/dev/bittiming.c

@@ -67,22 +67,18 @@ int can_get_bittiming(const struct net_device *dev, struct can_bittiming *bt,
 		      const u32 *bitrate_const,
 		      const unsigned int bitrate_const_cnt)
 {
-	int err;
-
 	/* Depending on the given can_bittiming parameter structure the CAN
 	 * timing parameters are calculated based on the provided bitrate OR
 	 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
 	 * provided directly which are then checked and fixed up.
 	 */
 	if (!bt->tq && bt->bitrate && btc)
-		err = can_calc_bittiming(dev, bt, btc);
-	else if (bt->tq && !bt->bitrate && btc)
-		err = can_fixup_bittiming(dev, bt, btc);
-	else if (!bt->tq && bt->bitrate && bitrate_const)
-		err = can_validate_bitrate(dev, bt, bitrate_const,
+		return can_calc_bittiming(dev, bt, btc);
+	if (bt->tq && !bt->bitrate && btc)
+		return can_fixup_bittiming(dev, bt, btc);
+	if (!bt->tq && bt->bitrate && bitrate_const)
+		return can_validate_bitrate(dev, bt, bitrate_const,
 					    bitrate_const_cnt);
-	else
-		err = -EINVAL;
 
-	return err;
+	return -EINVAL;
 }