Fix golangci-lint issues

As part of updating dapper files, golangci-lint was set to be used. This
caused a lot of lint issues to crop up, which this fixes.

controller/generic_controller.go

@@ -2,13 +2,10 @@ package controller
 
 import (
 	"context"
-	"strings"
 	"time"
 
-	errors2 "github.com/pkg/errors"
 	"github.com/rancher/lasso/pkg/controller"
 	"github.com/sirupsen/logrus"
-	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/tools/cache"
@@ -78,20 +75,3 @@ func isNamespace(namespace string, obj runtime.Object) bool {
 	}
 	return meta.GetNamespace() == namespace
 }
-
-func ignoreError(err error, checkString bool) bool {
-	err = errors2.Cause(err)
-	if errors.IsConflict(err) {
-		return true
-	}
-	if err == controller.ErrIgnore {
-		return true
-	}
-	if _, ok := err.(*ForgetError); ok {
-		return true
-	}
-	if checkString {
-		return strings.HasSuffix(err.Error(), "please apply your changes to the latest version and try again")
-	}
-	return false
-}