add tailing period for comment

Signed-off-by: yapo.yang <yang_yapo@126.com>

cmd/thanos/rule.go

@@ -425,10 +425,10 @@ func runRule(
 		g.Add(func() error {
 			c := make(chan os.Signal, 1)
 			signal.Notify(c, syscall.SIGHUP)
-			//initialize rules
+			//initialize rules.
 			if err := reloadRules(logger, ruleFiles, ruleMgr, evalInterval, configSuccess, configSuccessTime, rulesLoaded); err != nil {
 				level.Error(logger).Log("msg", "initialize rules failed", "err", err)
-				//returns when initialize with invalid pattern error
+				//returns when initialize with invalid pattern error.
 				if _, ok := err.(*errInvalidPattern); ok {
 					return err
 				}
@@ -783,7 +783,7 @@ func reloadRules(logger log.Logger,
 	for _, pat := range ruleFiles {
 		fs, err := filepath.Glob(pat)
 		if err != nil {
-			//check errInvalidPattern when initialize
+			//check errInvalidPattern when initialize.
 			return &errInvalidPattern{err, pat}
 		}