can: omit received RTR frames for single ID filter lists

Since commit d253eee2

 the single CAN
identifier filter lists handle only non-RTR CAN frames.

So we need to omit the check of these filter lists when receiving RTR
CAN frames.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>