MFC r316501, r316523

MFC r316501, r316523

r316501:
Fix file descriptor and memory leaks in pr(1)

Also, hook NetBSD's pr test into the build, and add three more test cases.

Reported by:	Coverity, Valgrind
CID:		271650 271651 271652 271653 271654 271655 271656 271656
CID:		271657 271658 271659 1006939 1006940 1006941 1006942 1009098
Reviewed by:	ngie
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D9137

r316523:
Remove a duplicate fclose() that snuck into r316501

Reported by:	Coverity
CID:		1373338
X-MFC-With:	316501
Sponsored by:	Spectra Logic Corp

git-svn-id: svn://svn.freebsd.org/base/stable/10@319257 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f