Fix docstrings in enforce() and check() policy methods
Fix docstrings in enforce() and check() policy methods

Proper name of the  parameter is 'target', not 'object'.

Change-Id: Ia7a671c9aed644137e4c46452d8d8bf3bc3f2eee

darren-wang/gl,klmitch/glance,rajalokan/glance,wkoathp/glance,openstack/glance,sigmavirus24/glance,wkoathp/glance,kfwang/Glance-OVA-OVF,takeshineshiro/glance,dims/glance,takeshineshiro/glance,akash1808/glance,stevelle/glance,paramite/glance,saeki-masaki/glance,rajalokan/glance,sigmavirus24/glance,darren-wang/gl,JioCloud/glance,ozamiatin/glance,JioCloud/glance,scripnichenko/glance,jumpstarter-io/glance,stevelle/glance,redhat-openstack/glance,klmitch/glance,saeki-masaki/glance,openstack/glance,vuntz/glance,jumpstarter-io/glance,openstack/glance,scripnichenko/glance,paramite/glance,dims/glance,kfwang/Glance-OVA-OVF,akash1808/glance,ozamiatin/glance,vuntz/glance,redhat-openstack/glance