simplify string output

pkg/minikube/cni/bridge.go

@@ -54,7 +54,7 @@ type Bridge struct {
 
 // String returns a string representation of this CNI
 func (c Bridge) String() string {
-	return "Bridge CNI"
+	return "bridge CNI"
 }
 
 func (c Bridge) netconf() (assets.CopyableFile, error) {

pkg/minikube/cni/custom.go

@@ -17,7 +17,6 @@ limitations under the License.
 package cni
 
 import (
-	"fmt"
 	"os"
 	"path"
 
@@ -34,7 +33,7 @@ type Custom struct {
 
 // String returns a string representation of this CNI
 func (c Custom) String() string {
-	return fmt.Sprintf("Custom (%s)", c.manifest)
+	return c.manifest
 }
 
 // NewCustom returns a well-formed Custom CNI manager