MFC r330771:
Remove obsoleted and unused key_sendup() function. Also remove declaration for nonexistend key_usrreq() function.
MFC r330772:
Check that we have PF_KEY sockets before iterating over all RAW sockets.
MFC r330775:
Replace panic() with KASSERTs.
MFC r330777:
Add KASSERT to check that proper targed was used.