selftests: net: cmsg_so_mark: test with SO_MARK set by setsockopt
Test if setting SO_MARK with setsockopt works and if cmsg
takes precedence over it.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
authored by