migration: catch unknown flags in ram_load

migration: catch unknown flags in ram_load

if a saved vm has unknown flags in the memory data qemu
currently simply ignores this flag and continues which
yields in an unpredictable result.

This patch catches all unknown flags and aborts the
loading of the vm. Additionally error reports are thrown
if the migration aborts abnormally.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
(cherry picked from commit db80facefa62dff42bb50c73b0f03eda5f732b49)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>