qdev: Replace cannot_instantiate_with_device_add_yet with !user_creatable

qdev: Replace cannot_instantiate_with_device_add_yet with !user_creatable

cannot_instantiate_with_device_add_yet was introduced by commit
efec3dd631d94160288392721a5f9c39e50fb2bc to replace no_user. It was
supposed to be a temporary measure.

When it was introduced, we had 54
cannot_instantiate_with_device_add_yet=true lines in the code.
Today (3 years later) this number has not shrunk: we now have
57 cannot_instantiate_with_device_add_yet=true lines. I think it
is safe to say it is not a temporary measure, and we won't see
the flag go away soon.

Instead of a long field name that misleads people to believe it
is temporary, replace it a shorter and less misleading field:
user_creatable.

Except for code comments, changes were generated using the
following Coccinelle patch:

  @@
  expression DC;
  @@
  (
  -DC->cannot_instantiate_with_device_add_yet = false;
  +DC->user_creatable = true;
  |
  -DC->cannot_instantiate_with_device_add_yet = true;
  +DC->user_creatable = false;
  )

  @@
  typedef ObjectClass;
  expression dc;
  identifier class, data;
  @@
   static void device_class_init(ObjectClass *class, void *data)
   {
   ...
   dc->hotpluggable = true;
  +dc->user_creatable = true;
   ...
   }

  @@
  @@
   struct DeviceClass {
   ...
  -bool cannot_instantiate_with_device_add_yet;
  +bool user_creatable;
   ...
  }

  @@
  expression DC;
  @@
  (
  -!DC->cannot_instantiate_with_device_add_yet
  +DC->user_creatable
  |
  -DC->cannot_instantiate_with_device_add_yet
  +!DC->user_creatable
  )

Cc: Alistair Francis <alistair.francis@xilinx.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Thomas Huth <thuth@redhat.com>
Acked-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Acked-by: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170503203604.31462-2-ehabkost@redhat.com>
[ehabkost: kept "TODO remove once we're there" comment]
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
(cherry picked from commit e90f2a8c3e0e677eeea46a9b401c3f98425ffa37)
 Conflicts:
	include/hw/qdev-core.h
* remove context dep on 08f00df
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>