Fix DB query call
Fix DB query call

Commit dfdf67a51b6a1883e3906fdba2d3f7ca2365f0c2 introduced a bulk
get for subnets. Two of the parameters for the "_get_collection"
API were switched (filters and dict_func) for the call. The
filters parameter is kwargs, but the dict_func is positional,
so we have to switch them back.

Change-Id: I81dbe7bd45858e5bb6fd43cb6030e594b1015325

noironetworks/group-based-policy,noironetworks/group-based-policy