chattr fails tests on non ext,xfs filesystems

[Mike Grayson]

In file coreutils-6.3/tests/tail-2/append-only, lines 2-3:

# Ensure that tail -f works on an append-only file
# Requires root access to do chattr +a, as well as an ext[23] or xfs file
system


...which causes the test suite to fail on non supporting filesystems.  It
would be better if this test would be skipped instead.

thx,
mg