test(juicefs): remove redundant ControllerName assertion

Remove the duplicate assertion that tested against the unexported
constant; use the string literal form only as suggested by code review.

Signed-off-by: Harsh <harshmastic@gmail.com>

Author: hxrshxz

pkg/controllers/v1alpha1/juicefs/juicefsruntime_controller_test.go

@@ -35,7 +35,6 @@ var _ = Describe("JuiceFSRuntimeReconciler", func() {
 	Describe("ControllerName", func() {
 		It("should return the constant controller name", func() {
 			r := &JuiceFSRuntimeReconciler{}
-			Expect(r.ControllerName()).To(Equal(controllerName))
 			Expect(r.ControllerName()).To(Equal("JuiceFSRuntimeController"))
 		})
 	})