Fix some typos in comments. (#4100)

Signed-off-by: Hu Shuai <hus.fnst@cn.fujitsu.com>

plugin/kubernetes/autopath.go

@@ -49,7 +49,7 @@ func (k *Kubernetes) AutoPath(state request.Request) []string {
 	return search
 }
 
-// podWithIP return the api.Pod for source IP. It returns nil if nothing can be found.
+// podWithIP returns the api.Pod for source IP. It returns nil if nothing can be found.
 func (k *Kubernetes) podWithIP(ip string) *object.Pod {
 	if k.podMode != podModeVerified {
 		return nil

plugin/kubernetes/object/endpoint.go

@@ -42,7 +42,7 @@ type EndpointPort struct {
 	Protocol string
 }
 
-// EndpointsKey return a string using for the index.
+// EndpointsKey returns a string using for the index.
 func EndpointsKey(name, namespace string) string { return name + "." + namespace }
 
 // ToEndpoints returns a function that converts an *api.Endpoints to a *Endpoints.

plugin/kubernetes/object/service.go

@@ -25,7 +25,7 @@ type Service struct {
 	*Empty
 }
 
-// ServiceKey return a string using for the index.
+// ServiceKey returns a string using for the index.
 func ServiceKey(name, namespace string) string { return name + "." + namespace }
 
 // ToService returns a function that converts an api.Service to a *Service.

plugin/kubernetes/parse.go

@@ -99,7 +99,7 @@ func stripUnderscore(s string) string {
 	return s[1:]
 }
 
-// String return a string representation of r, it just returns all fields concatenated with dots.
+// String returns a string representation of r, it just returns all fields concatenated with dots.
 // This is mostly used in tests.
 func (r recordRequest) String() string {
 	s := r.port