can: kvaser_pciefd: Empty SRB buffer in probe

Empty the "Shared receive buffer" (SRB) in probe, to assure we start in a
known state, and don't process any irrelevant packets.

Fixes: 26ad340e ("can: kvaser_pciefd: Add driver for Kvaser PCIEcan devices")
Cc: stable@vger.kernel.org
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://lore.kernel.org/r/20230516134318.104279-5-extja@kvaser.com


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