common/attr: fix the _require_acl test

common/attr: fix the _require_acl test

_require_acl tests whether you're able to fetch the ACL from a file
using chacl, and then tests for an -EOPNOTSUPP error return.
Unfortunately, filesystems that don't support them (like NFSv4) just
return -ENODATA when someone calls getxattr for the POSIX ACL, so the
test doesn't work.

Fix the test to have chacl set an ACL on the file instead, which should
reliably fail on filesystems that don't support them.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Zorro Lang <zlang@kernel.org>