[1.6.x] Fixed #21908 -- Added example usage for ModelAdmin.get_inline_instances().
[1.6.x] Fixed #21908 -- Added example usage for ModelAdmin.get_inline_instances().

Thanks matt at schinckel.net for the suggestion.

Backport of 5a4f1298cf from master

felixjimenez/django,felixjimenez/django,redhat-openstack/django,redhat-openstack/django,redhat-openstack/django,django-nonrel/django,django-nonrel/django,felixjimenez/django,django-nonrel/django,felixjimenez/django,redhat-openstack/django,django-nonrel/django