gci: fix options display (golangci#2989)

Author: oscr

pkg/golinters/gci.go

@@ -141,7 +141,7 @@ func getErrorTextForGci(settings config.GciSettings) string {
 	text += " with"
 
 	if settings.SkipGenerated {
-		text += " -skip-generated"
+		text += " --skip-generated"
 	}
 
 	if len(settings.Sections) > 0 {

test/testdata/gci.go

@@ -5,9 +5,9 @@ package testdata
 import (
 	"fmt"
 
-	"github.com/golangci/golangci-lint/pkg/config" // ERROR "File is not \\`gci\\`-ed with -skip-generated -s standard,prefix\\(github.com/golangci/golangci-lint\\),default"
+	"github.com/golangci/golangci-lint/pkg/config" // ERROR "File is not \\`gci\\`-ed with --skip-generated -s standard,prefix\\(github.com/golangci/golangci-lint\\),default"
 
-	"github.com/pkg/errors" // ERROR "File is not \\`gci\\`-ed with -skip-generated -s standard,prefix\\(github.com/golangci/golangci-lint\\),default"
+	"github.com/pkg/errors" // ERROR "File is not \\`gci\\`-ed with --skip-generated -s standard,prefix\\(github.com/golangci/golangci-lint\\),default"
 )
 
 func GoimportsLocalTest() {