Fix with gofmt -s -w for plugin/tls/tls_test.go (#1552)

to make goreportcard happy
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

plugin/tls/tls_test.go

@@ -18,8 +18,8 @@ func TestTLS(t *testing.T) {
 		expectedRoot       string // expected root, set to the controller. Empty for negative cases.
 		expectedErrContent string // substring from the expected error. Empty for positive cases.
 	}{
-		// positive
-		// negative
+	// positive
+	// negative
 	}
 
 	for i, test := range tests {