can: statistics: add missing atomic access in hot path

Commit 80b5f90158d1 ("can: statistics: use atomic access in hot path")
fixed a KCSAN issue in can_receive() but missed to convert the 'matches'
variable used in can_rcv_filter().

Fixes: 80b5f90158d1 ("can: statistics: use atomic access in hot path")
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260318173413.28235-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>