all: make staticcheck happier (#1150)

* a value (allocation) that was never used
* unused field (fine to remove as per the library)
* simplify error return

analytics.go

@@ -49,8 +49,7 @@ type GeoData struct {
 	} `maxminddb:"country"`
 
 	City struct {
-		GeoNameID uint              `maxminddb:"geoname_id"`
-		Names     map[string]string `maxminddb:"names"`
+		Names map[string]string `maxminddb:"names"`
 	} `maxminddb:"city"`
 
 	Location struct {

main.go

@@ -226,7 +226,7 @@ func getAPISpecs() []*APISpec {
 }
 
 func getPolicies() {
-	pols := make(map[string]Policy)
+	var pols map[string]Policy
 	log.WithFields(logrus.Fields{
 		"prefix": "main",
 	}).Info("Loading policies")

res_handler_header_injector.go

@@ -20,10 +20,7 @@ type HeaderInjector struct {
 
 func (h *HeaderInjector) Init(c interface{}, spec *APISpec) error {
 	h.Spec = spec
-	if err := mapstructure.Decode(c, &h.config); err != nil {
-		return err
-	}
-	return nil
+	return mapstructure.Decode(c, &h.config)
 }
 
 func (h *HeaderInjector) HandleResponse(rw http.ResponseWriter, res *http.Response, req *http.Request, ses *SessionState) error {