git: DragonFly_RELEASE_5_2 kernel - MFC pmap panic fix from master

[Matthew Dillon]

commit fd8dd750559eb60ff12f97e27372492536ffb47f
Author: Matthew Dillon <***@apollo.backplane.com>
Date: Mon Oct 29 16:27:17 2018 -0700

kernel - MFC pmap panic fix from master

* MFC the pd_pv test for certain race case retries in the pmap
code. pv_put() was being called unconditionally on a pd_pv
pointer that could be NULL.

Reported-by: gjs278

Summary of changes:
sys/platform/pc64/x86_64/pmap.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/fd8dd750559eb60ff12f97e27372492536ffb47f