This patch introduces a function that reverses everything
done by vmbus_allocate_mmio().  Existing code just called
release_mem_region().  Future patches in this series
require a more complex sequence of actions, so this function
is introduced to wrap those actions.
Signed-off-by: NJake Oshins <jakeo@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>