Revert MFC of r313045 from stable/10

[smh]

Summary

Revert the partial MFC of r313045 from stable/10 which broke dtrace.

This removes the mbuf to ipinfo_t translator and switches tcp_autorcvbuf to use the older mtod macro.

Test Plan

1. Compile kernel.
2. Confirm that dtrace works.

[markj]

I'm not set up to test this, but it looks right to me.

[hiren]

Do mention stable/10 rev also in your commit.