removing inner goroutine in cluster.Switchover (#1876)

* removing inner goroutine in cluster.Switchover and resolve race between processPodEvent and unregisterPodSubscriber
* unlock mutex after handling event, now with non-blocking default case

pkg/util/util.go

@@ -324,12 +324,20 @@ func testNil(values ...*int32) bool {
 	return false
 }
 
-// Convert int to IntOrString type
+// ToIntStr converts int to IntOrString type
 func ToIntStr(val int) *intstr.IntOrString {
 	b := intstr.FromInt(val)
 	return &b
 }
 
+// Bool2Int converts bool to int
+func Bool2Int(flag bool) int {
+	if flag {
+		return 1
+	}
+	return 0
+}
+
 // Get int from IntOrString and return max int if string
 func IntFromIntStr(intOrStr intstr.IntOrString) int {
 	if intOrStr.Type == 1 {