can: mcp251xfd: mcp251xfd_probe(): add missing can_rx_offload_del() in error path

This patch adds the missing can_rx_offload_del(), that must be called
if mcp251xfd_register() fails.

Fixes: 55e5b97f ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN")
Link: https://lore.kernel.org/r/20210504091838.1109047-1-mkl@pengutronix.de


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>