can: f81604: f81604_handle_can_bus_errors(): fix {rx,tx}_errors statistics

can: f81604: f81604_handle_can_bus_errors(): fix {rx,tx}_errors statistics

The f81604_handle_can_bus_errors() function only incremented the receive
error counter and never the transmit error counter, even if the ECC_DIR
flag reported that an error had occurred during transmission.

Increment the receive/transmit error counter based on the value of the
ECC_DIR flag.

Fixes: 88da17436973 ("can: usb: f81604: add Fintek F81604 support")
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Link: https://patch.msgid.link/20241122221650.633981-13-dario.binacchi@amarulasolutions.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>