FreeBSD_HEAD_i386 - Build #3134 - Fixed

FreeBSD_HEAD_i386 - Build #3134 - Fixed:

Build information: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/3134/
Full change log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/3134/changes
Full build log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/3134/console

Change summaries:

299942 by jilles:
install: Revert utimensat usage (r299850).

This should fix the build on older stable/10, since install is a bootstrap
tool.

Pending a decision how to fix this properly, revert utimensat usage. Copies
with the -p option will again appear older than the original almost always,
but -p is not commonly used.

299941 by andrew:
Call ofw_bus_msimap to find the parent MSI controller, it may not use the
msi-parent property.

Obtained from:	ABT Systems Ltd
Sponsored by:	The FreeBSD Foundation

299940 by avg:
fix a vnode reference leak caused by illumos compat traverse()

This commit partially reverts r273641 which introduced the leak.
It did so to accomodate for some consumers of traverse() that expected
the starting vnode to stay as-is.  But that introduced the leak in the
case when a mounted filesystem was found and its root vnode was
returned.

r299914 removed the troublesome consumers and now there is no reason to
keep the starting vnode.  So, now the new rules are:
- if there is no mounted filesystem, then nothing is changed
- otherwise the starting vnode is always released
- the root vnode of the mounted filesystem is returned locked and
  referenced in the case of success

MFC after:	5 weeks
X-MFC after:	r299914

299939 by andrew:
Move the call to intr_pic_init_secondary to the same place as in the
non-intrng case.

Obtained from:	ABT Systems Ltd
Sponsored by:	The FreeBSD Foundation

299938 by avg:
fix up r299902: mount_snapshot requires that the covered vnode is locked

Previously that was not strictly enforced.

MFC after:	4 weeks
X-MFC with:	r299902