[NFCT.NS.1] Respect the nlfamily in the netlink message parsing

The netlink message parsing requires the netlink family except the
reserved control message. Here is an example. If the netlink family
is not provided, the netlink message parser may not be able to
distinguish which netlink family it belongs to by netlink message
type 20.
    NETLINK_ROUTE.RTM_NEWADDR (20)
    NETLINK_SOCK_DIAG.SOCK_DIAG_BY_FAMILY (20)

Test: atest TetheringCoverageTest
Change-Id: I04ef64828e6b2a5ac62a28895da7bc71d06fcb9b