cam: introduce xpt_setup_stack_ccb

[imp]

Summary

Create a new function xpt_setup_stack_ccb which is used to setup a ccb
that lives on the stack.

Sponsored by: Netflix

Test Plan

This is a thought experiment on how one might create a safer version of this that we could assert on later.

[imp]

Add malloc tagging and add assert to xpt_setup_ccb

[imp]

Note: this just does scsi_da.c as a proof of concept, but doesn't go through the tree yet.

[imp]

This comment was removed by imp.

[imp]

https://reviews.freebsd.org/D30353 has all the other changes, and a good coccinelle script for spatch

[imp]

tweak the script to eliminate a couple of bugs

[imp]

better script

[imp]

oops, regen with right patch

[imp]

assert we're not freeing a stack thing
Get the names of the field right

[imp]

I still like this idea, but I think that I'm just going to punt on this detail