Fix some linter issues

selector/cache/cache.go

@@ -366,11 +366,9 @@ func (c *cacheSelector) Select(service string, opts ...selector.SelectOption) (s
 }
 
 func (c *cacheSelector) Mark(service string, node *registry.Node, err error) {
-	return
 }
 
 func (c *cacheSelector) Reset(service string) {
-	return
 }
 
 // Close stops the watcher and destroys the cache

selector/default.go

@@ -48,11 +48,9 @@ func (r *defaultSelector) Select(service string, opts ...SelectOption) (Next, er
 }
 
 func (r *defaultSelector) Mark(service string, node *registry.Node, err error) {
-	return
 }
 
 func (r *defaultSelector) Reset(service string) {
-	return
 }
 
 func (r *defaultSelector) Close() error {

selector/filter_test.go

@@ -80,7 +80,7 @@ func TestFilterEndpoint(t *testing.T) {
 				}
 			}
 
-			if seen == false && data.count > 0 {
+			if !seen && data.count > 0 {
 				t.Fatalf("Expected %d services but seen is %t; result %+v", data.count, seen, services)
 			}
 		}
@@ -232,7 +232,7 @@ func TestFilterVersion(t *testing.T) {
 			seen = true
 		}
 
-		if seen == false && data.count > 0 {
+		if !seen && data.count > 0 {
 			t.Fatalf("Expected %d services but seen is %t; result %+v", data.count, seen, services)
 		}
 	}