some code simplification, enabled type assertion in errcheck again

.golangci.yml

controller/nucleus/deviceWatcher.go

controller/nucleus/errors/errors.go

controller/nucleus/gnmi_transport_test.go

controller/topology/nodes/nodeStore.go

controller/topology/ports/portStore.go

controller/topology/routing-tables/routingTableStore.go

controller/topology/topologyStore.go

csbi/repository.go