Update the "first appeared in" version in several manual pages.

MFC after:	3 days
Sponsored by:	The FreeBSD Foundation

sbin/zfsbootcfg/zfsbootcfg.8

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 12, 2016
+.Dd May 24, 2017
 .Dt ZFSBOOTCFG 8
 .Os
 .Sh NAME
@@ -86,7 +86,7 @@ To clear the boot options:
 .Sh HISTORY
 .Nm
 appeared in
-.Fx 12.0 .
+.Fx 11.1 .
 .Sh AUTHORS
 This manual page was written by
 .An Andriy Gapon Aq Mt avg@FreeBSD.org .

share/man/man9/mutex.9

@@ -28,7 +28,7 @@
 .\"	from BSDI $Id: mutex.4,v 1.1.2.3 1998/04/27 22:53:13 ewv Exp $
 .\" $FreeBSD$
 .\"
-.Dd July 18, 2016
+.Dd May 24, 2017
 .Dt MUTEX 9
 .Os
 .Sh NAME
@@ -557,4 +557,4 @@ and
 The
 .Fn mtx_trylock_spin
 function was added in
-.Fx 12.0 .
+.Fx 11.1 .

usr.sbin/efidp/efidp.8

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 5, 2017
+.Dd May 24, 2017
 .Dt EFIDP 8
 .Os
 .Sh NAME
@@ -50,4 +50,4 @@ have the format described in RFC 4122.
 The
 .Nm
 utility first appeared in
-.Fx 12.0 .
+.Fx 11.1 .