MFC r258041:

Mention acl_get_brand_np(3).

Approved by:	re (gjb)
Sponsored by:	The FreeBSD Foundation
MFC r258042:

Fix description to actually make sense.

Approved by:	re (gjb)
Sponsored by:	The FreeBSD Foundation
MFC r258043:

Fix typo.

Approved by:	re (gjb)
Sponsored by:	The FreeBSD Foundation
Merge branch 'stable/10' of https://github.com/freebsd/freebsd into stable/10