Fix new lints

internal/api/commitment.go

@@ -305,7 +305,7 @@ func (p *v1Provider) CreateProjectCommitment(w http.ResponseWriter, r *http.Requ
 	}
 	if minConfirmBy := behavior.CommitmentMinConfirmDate; minConfirmBy != nil && minConfirmBy.After(now) {
 		if req.ConfirmBy == nil || req.ConfirmBy.Before(*minConfirmBy) {
-			msg := fmt.Sprintf("this commitment needs a `confirm_by` timestamp at or after %s", behavior.CommitmentMinConfirmDate.Format(time.RFC3339))
+			msg := "this commitment needs a `confirm_by` timestamp at or after " + behavior.CommitmentMinConfirmDate.Format(time.RFC3339)
 			http.Error(w, msg, http.StatusUnprocessableEntity)
 			return
 		}

internal/api/quota_updater.go

@@ -336,7 +336,7 @@ func (u QuotaUpdater) validateQuota(srv limes.ServiceInfo, res limesresources.Re
 	verr = u.validateAuthorization(srv, res, oldQuota, newQuota, lprLimit, lprIsReversible, res.Unit)
 	if verr != nil {
 		if verr.Status == http.StatusForbidden {
-			verr.Message += fmt.Sprintf(" in this %s", u.ScopeType())
+			verr.Message += " in this " + u.ScopeType()
 		}
 		return verr
 	}

internal/plugins/keppel.go

@@ -19,7 +19,7 @@
 package plugins
 
 import (
-	"fmt"
+	"errors"
 	"math/big"
 	"net/http"
 
@@ -112,7 +112,7 @@ func (p *keppelPlugin) IsQuotaAcceptableForProject(project core.KeystoneProject,
 	}
 	if swiftQuotas["capacity"] == 0 && ourQuotas["images"] > 0 {
 		//nolint:stylecheck // "Keppel" is a product name and thus must be capitalized
-		return fmt.Errorf("Keppel can only be used when a nonzero Swift quota is configured")
+		return errors.New("Keppel can only be used when a nonzero Swift quota is configured")
 	}
 	return nil
 }