Fix golangci-lint warnings (#17598 et al) (#17668)

Backport #17598 
Backport #17606 
Backport #17608 
Backport #17609

- Since https://gitea.com/gitea/test-env/pulls/10 the golangci-lint has been upgraded and is erroring about new warnings in the code, this PR fixes those warnings.

modules/indexer/code/bleve.go

@@ -174,6 +174,10 @@ func NewBleveIndexer(indexDir string) (*BleveIndexer, bool, error) {
 		indexDir: indexDir,
 	}
 	created, err := indexer.init()
+	if err != nil {
+		indexer.Close()
+		return nil, false, err
+	}
 	return indexer, created, err
 }
 

modules/indexer/code/elastic_search.go

@@ -83,7 +83,10 @@ func NewElasticSearchIndexer(url, indexerName string) (*ElasticSearchIndexer, bo
 		indexerAliasName: indexerName,
 	}
 	exists, err := indexer.init()
-
+	if err != nil {
+		indexer.Close()
+		return nil, false, err
+	}
 	return indexer, !exists, err
 }
 

modules/indexer/code/indexer.go

@@ -188,9 +188,6 @@ func Init() {
 
 			rIndexer, populate, err = NewBleveIndexer(setting.Indexer.RepoPath)
 			if err != nil {
-				if rIndexer != nil {
-					rIndexer.Close()
-				}
 				cancel()
 				indexer.Close()
 				close(waitChannel)
@@ -208,9 +205,6 @@ func Init() {
 
 			rIndexer, populate, err = NewElasticSearchIndexer(setting.Indexer.RepoConnStr, setting.Indexer.RepoIndexerName)
 			if err != nil {
-				if rIndexer != nil {
-					rIndexer.Close()
-				}
 				cancel()
 				indexer.Close()
 				close(waitChannel)

modules/indexer/stats/queue.go

@@ -27,7 +27,7 @@ func handle(data ...queue.Data) {
 }
 
 func initStatsQueue() error {
-	statsQueue = queue.CreateUniqueQueue("repo_stats_update", handle, int64(0)).(queue.UniqueQueue)
+	statsQueue = queue.CreateUniqueQueue("repo_stats_update", handle, int64(0))
 	if statsQueue == nil {
 		return fmt.Errorf("Unable to create repo_stats_update Queue")
 	}