can: remove obsolete get_canfd_dlc() macro

The macro was always used together with can_dlc2len() which sanitizes the
given dlc value on its own.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-4-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

include/linux/can/dev/peak_canfd.h

@@ -282,7 +282,7 @@ static inline int pucan_msg_get_channel(const struct pucan_rx_msg *msg)
 }
 
 /* return the dlc value from any received message channel_dlc field */
-static inline int pucan_msg_get_dlc(const struct pucan_rx_msg *msg)
+static inline u8 pucan_msg_get_dlc(const struct pucan_rx_msg *msg)
 {
 	return msg->channel_dlc >> 4;
 }