can: Propagate SO_PRIORITY of raw sockets to skbs

can: Propagate SO_PRIORITY of raw sockets to skbs

This allows controlling certain queueing disciplines by setting the
socket's SO_PRIORITY option.

For example, with the default pfifo_fast queueing discipline, which
provides three priorities, socket priority TC_PRIO_CONTROL means
higher than default and TC_PRIO_BULK means lower than default.

Signed-off-by: Rostislav Lisovy <[email protected]>
Signed-off-by: Michal Sojka <[email protected]>
Acked-by: Oliver Hartkopp <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>