Fix gofmt and add it to the list of linters

Makefile

@@ -76,7 +76,7 @@ GOLINT_GOGC ?= 100
 # options for lint (golangci-lint)
 GOLINT_OPTIONS = --timeout 7m \
 	  --build-tags "${MINIKUBE_INTEGRATION_BUILD_TAGS}" \
-	  --enable goimports,gocritic,golint,gocyclo,misspell,nakedret,stylecheck,unconvert,unparam,dogsled \
+	  --enable gofmt,goimports,gocritic,golint,gocyclo,misspell,nakedret,stylecheck,unconvert,unparam,dogsled \
 	  --exclude 'variable on range scope.*in function literal|ifElseChain' \
 	  --skip-files "pkg/minikube/translate/translations.go|pkg/minikube/assets/assets.go"
 

pkg/minikube/perf/result_manager.go

@@ -37,7 +37,7 @@ func newResultManager() *resultManager {
 func (rm *resultManager) addResult(binary *Binary, test string, r result) {
 	a, ok := rm.results[binary]
 	if !ok {
-		r := map[string][]*result{test: []*result{&r}}
+		r := map[string][]*result{test: {&r}}
 		rm.results[binary] = resultWrapper{r}
 		return
 	}