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

tests/zfs-tests/tests/functional/acl/posix/posix_003_pos.ksh

@@ -25,7 +25,6 @@
 #
 # DESCRIPTION:
 #	Verify that ACLs survive remount.
-#	Regression test for https://github.com/zfsonlinux/zfs/issues/4520
 #
 # STRATEGY:
 #	1. Test presence of default and regular ACLs after remount

tests/zfs-tests/tests/functional/channel_program/synctask_core/tst.get_number_props.zcp

@@ -41,7 +41,7 @@ props['logicalused']          = {{true,       nil}, {nil,  nil}, {true,       ni
 props['logicalreferenced']    = {{true,       nil}, {true, nil}, {true,       nil}}
 props['quota']                = {{true, 'default'}, {nil,  nil}, {nil,        nil}}
 props['reservation']          = {{true, 'default'}, {nil,  nil}, {true, 'default'}}
--- Note that zfsonlinux allows volsize for snapshot which differs from openzfs
+-- Note that OpenZFS allows volsize for snapshot
 -- props['volsize']           = {{nil,        nil}, {nil,  nil}, {true,       vol}}
 props['refquota']             = {{true, 'default'}, {nil,  nil}, {nil,        nil}}
 props['refreservation']       = {{true, 'default'}, {nil,  nil}, {true,       vol}}

tests/zfs-tests/tests/functional/cli_root/zfs_mount/zfs_mount_test_race.ksh

@@ -26,7 +26,7 @@
 # under race condition which resulted in undefined mount order.  The purpose
 # of this test is to verify `zfs unmount -a` succeeds (not `zfs mount -a`
 # succeeds, it always does) after `zfs mount -a`, which could fail if threads
-# race.  See github.com/zfsonlinux/zfs/issues/{8450,8833,8878} for details.
+# race.  See github.com/openzfs/zfs/issues/{8450,8833,8878} for details.
 #
 # STRATEGY:
 # 1. Create pools and filesystems.

tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_sparse.ksh

@@ -24,7 +24,7 @@
 # 1. Create sparse files of various size
 # 2. Snapshot and send these sparse files
 # 3. Verify these files are received correctly and we don't trigger any issue
-#    like the one described in https://github.com/zfsonlinux/zfs/pull/6760
+#    like the one described in https://github.com/openzfs/zfs/pull/6760
 #
 
 verify_runnable "both"

tests/zfs-tests/tests/functional/rsend/rsend_008_pos.ksh

@@ -43,7 +43,7 @@
 
 verify_runnable "both"
 
-# See issue: https://github.com/zfsonlinux/zfs/issues/6066
+# See issue: https://github.com/openzfs/zfs/issues/6066
 log_unsupported "Occasionally hangs"
 
 #		Origin			Clone

tests/zfs-tests/tests/functional/rsend/send_freeobjects.ksh

@@ -21,7 +21,7 @@
 #
 # Description:
 # Verify FREEOBJECTS record frees sequential objects (See
-# https://github.com/zfsonlinux/zfs/issues/6694)
+# https://github.com/openzfs/zfs/issues/6694)
 #
 # Strategy:
 # 1. Create three files with sequential object numbers, f1 f2 and f3