block: Code motion to get rid of stubs/blockdev.c Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: BenoƮt Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>