MFC 359071: Document that posixshmcontrol first appeared in 12.1 Also while here, I am addressing some linting issues. PR: 243132 Submitted by: Noah Altunian <nbaltunian gmail com> Approved by: bcr (mentor) Differential Revision: https://reviews.freebsd.org/D24112
stable/12/
stable/12/usr.bin/posixshmcontrol/posixshmcontrol.1