Fix a man page link in zfs-program.8

zfs-program.8 has an orphan link, fix it.

https://svnweb.freebsd.org/base?view=revision&revision=360080

Obtained from: FreeBSD
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alan Somers <asomers@gmail.com>
Closes #11529

man/man8/zfs-program.8

@@ -12,7 +12,7 @@
 .\" Copyright (c) 2019, 2020 by Christian Schwarz. All Rights Reserved.
 .\" Copyright 2020 Joyent, Inc.
 .\"
-.Dd February 3, 2020
+.Dd January 26, 2021
 .Dt ZFS-PROGRAM 8
 .Os
 .Sh NAME
@@ -290,7 +290,7 @@ EBADF     EXDEV       EFBIG
 .Ss API Functions
 For detailed descriptions of the exact behavior of any zfs administrative
 operations, see the main
-.Xr zfs 1
+.Xr zfs 8
 manual page.
 .Bl -tag -width "xx"
 .It Em zfs.debug(msg)