Before 4.0, reading attrib/emulate_fua_write has returned 1. Saved
configs created on a pre-4.0 kernel will try to write that back when
restoring LIO configuration. This should succeed with no effect,
and issue a warning.

See https://bugzilla.redhat.com/show_bug.cgi?id=1206184Reported-by: NYanko Kaneti <yaneti@declera.com>
Reported-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAndy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>