Replace ZFS on Linux references with OpenZFS

This change updates the documentation to refer to the project
as OpenZFS instead ZFS on Linux.  Web links have been updated
to refer to https://github.com/openzfs/zfs.  The extraneous
zfsonlinux.org web links in the ZED and SPL sources have been
dropped.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11007

contrib/dracut/90zfs/module-setup.sh.in

@@ -41,7 +41,8 @@ install() {
 	dracut_install @bindir@/zgenhostid
 	dracut_install @sbindir@/zfs
 	dracut_install @sbindir@/zpool
-	# Workaround for zfsonlinux/zfs#4749 by ensuring libgcc_s.so(.1) is included
+	# Workaround for https://github.com/openzfs/zfs/issues/4749 by
+	# ensuring libgcc_s.so(.1) is included
 	if [[ -n "$(ldd @sbindir@/zpool | grep -F 'libgcc_s.so')" ]]; then
 		# Dracut will have already tracked and included it
 		:;

contrib/pyzfs/README

@@ -25,4 +25,4 @@ a temporary directory specified by, for instance, TMP environment
 variable on a memory backed filesystem.
 
 Package documentation: http://pyzfs.readthedocs.org
-Package development: https://github.com/zfsonlinux/zfs
+Package development: https://github.com/openzfs/zfs

contrib/pyzfs/libzfs_core/__init__.py

@@ -32,7 +32,7 @@ of the error codes to the exceptions by interpreting a context
 in which the error code is produced.
 
 To submit an issue or contribute to development of this package
-please visit its `GitHub repository <https://github.com/zfsonlinux/zfs>`_.
+please visit its `GitHub repository <https://github.com/openzfs/zfs>`_.
 
 .. data:: MAXNAMELEN