vfio/vfio-container.h: rename VFIOContainer bcontainer field to parent_obj

Now that nothing accesses the bcontainer field directly, rename bcontainer to
parent_obj as per our current coding guidelines.

Signed-off-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/qemu-devel/20250715093110.107317-8-mark.caveayland@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
diff --git a/include/hw/vfio/vfio-container.h b/include/hw/vfio/vfio-container.h
index 50c9178..240f566 100644
--- a/include/hw/vfio/vfio-container.h
+++ b/include/hw/vfio/vfio-container.h
@@ -26,7 +26,7 @@
 } VFIOGroup;
 
 struct VFIOContainer {
-    VFIOContainerBase bcontainer;
+    VFIOContainerBase parent_obj;
 
     int fd; /* /dev/vfio/vfio, empowered by the attached groups */
     unsigned iommu_type;