memory: Fix the memory region type assignment order

memory: Fix the memory region type assignment order

Currently, a callback registered through the RAMBlock notifier
is not able to get the memory region type (i.e callback is not
able to use memory_region_is_ram_device function). This is
because mr->ram assignment happens _after_ the memory is allocated
whereas the callback is executed during allocation.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1667249
Suggested-by: Alex Williamson <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Reviewed-by: Alex Williamson <[email protected]>
Signed-off-by: Brijesh Singh <[email protected]>
Message-Id: <20190204222322[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>