Fix leak of memory and file refs with sendmsg(2) over unix domain sockets.

[kib]

Summary

When sendmsg(2) sucessfully internalized one SCM_RIGHTS control message, but failed to process some other control message later, both file references and filedescent memory needs to be freed. This was not done, only mbuf chain was freed.

Noted by: markj

[markj]

sys/kern/uipc_usrreq.c

2124

td seems to be unused.

2164–2166

Could you move the initialization of control here? I think that would make it a bit easier to see what's going on.

2168

I don't understand where the name icontrolp comes from.

[kib]

sys/kern/uipc_usrreq.c

2168

Do you mean that you do not see what the contraction means ? I renamed the var to initial_controlp.

[kib]

Remove unused arg.
Move initializations around.
Rename the var.

[markj]

sys/kern/uipc_usrreq.c

2168

Ah, I assumed it meant "input controlp".