When reseeding the DPRNG, we're supposed to hash the current key and
some accumulated entropy twice and use that as the new key.  Due to a
typo, we were using the output of the first hash round instead of the
second.  Correct this, but eliminate temp[] since we can reuse hash[].
Also add comments explaining what is going on and why.

Noticed by:	Sami Farin <sami.farin@gmail.com>
Reviewed by:	markm@
Approved by:	so (des)
Partially fix indentation issues to improve readability helping cooperation with
Dragonfly folks

PR:		194785
Submitted by:	François Tigeot (ftigeot@wolfpond.org)