can: peak_usb: remove unused variables from struct peak_usb_device

This patch removes the unused variables struct
peak_usb_device::echo_skb and struct peak_usb_device::bus_load from
the driver.

Link: https://lore.kernel.org/r/20210406111622.1874957-4-mkl@pengutronix.deAcked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Tested-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/peak_usb/pcan_usb_core.h

@@ -114,8 +114,6 @@ struct peak_usb_device {
 	unsigned int ctrl_idx;
 	u32 state;
 
-	struct sk_buff *echo_skb[PCAN_USB_MAX_TX_URBS];
-
 	struct usb_device *udev;
 	struct net_device *netdev;
 
@@ -132,8 +130,6 @@ struct peak_usb_device {
 	u8 ep_msg_in;
 	u8 ep_msg_out;
 
-	u16 bus_load;
-
 	struct peak_usb_device *prev_siblings;
 	struct peak_usb_device *next_siblings;
 };