MFC r322770, r322796:

r322770:
Apply changes from bin/chmod/tests/chmod_test.sh, adding
atf_expect_fail() before chflags(8) is invoked if the filesystem
is ZFS, which does not support UF_IMMUTABLE.

r322796:
Revert part of r322770 in usr.sbin/chown/tests/chown_test.sh,
which incorrectly adds atf_expect_fail() where there is no
failure case.

Approved by: re (marius)
Sponsored by: The FreeBSD Foundation

MFC r268030,r268793,r303212,r319642,r319830:

r268030 (by eadler):

chown: add a test

Add a test for the chown utility. This sets up chown(8) to be capable of being
tested. As such, only add one test for now as an example.

r268793 (by eadler):

chown: Fix chown test number

r303212 (by bdrewery):

Move chown tests to proper path

r319642:

Add some basic tests for chmod(1)

r319830:

Add more simple positive tests for chown(1)

The tests are largely symmetric with the tests for chmod(1)--added in r319642.

Remove chown-f_test (added in r268030) since the test coverage is now being
provided by `chown_test`.

chown: add a test

Add a test for the chown utility. This sets up chown(8) to be capable of being
tested. As such, only add one test for now as an example.