Remove a spurious call to kfree_skb() in the connector rx_skb handler.

This fixes a regression introduced by the '[NET]: make netlink user ->
kernel interface synchronious' patch (cd40b7d3)
Signed-off-by: Michal Januszewski <spock@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>