MM-31064: Simplify indentation (#16565)

* MM-31064: Simplify indentation

Reduce indentation where possible.

```release-note
NONE
```

Command ran to verify:
golangci-lint run --disable-all --enable golint --max-issues-per-linter=10000 --max-same-issues=100000 ./... | grep "block ends with a return state"

https://mattermost.atlassian.net/browse/MM-31064

* incorporate review comments

* enable golint for outdent rule

* fix remaining issues

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

services/filesstore/s3store.go

@@ -171,11 +171,11 @@ func (b *S3FileBackend) ReadFile(path string) ([]byte, error) {
 	}
 
 	defer minioObject.Close()
-	if f, err := ioutil.ReadAll(minioObject); err != nil {
+	f, err := ioutil.ReadAll(minioObject)
+	if err != nil {
 		return nil, errors.Wrapf(err, "unable to read file %s", path)
-	} else {
-		return f, nil
 	}
+	return f, nil
 }
 
 func (b *S3FileBackend) FileExists(path string) (bool, error) {

services/searchengine/bleveengine/indexer/indexing_job.go

@@ -288,12 +288,11 @@ func (worker *BleveIndexerWorker) IndexPostsBatch(progress IndexingProgress) (In
 		if err != nil {
 			if tries >= 10 {
 				return progress, model.NewAppError("IndexPostsBatch", "app.post.get_posts_batch_for_indexing.get.app_error", nil, err.Error(), http.StatusInternalServerError)
-			} else {
-				mlog.Warn("Failed to get posts batch for indexing. Retrying.", mlog.Err(err))
-
-				// Wait a bit before trying again.
-				time.Sleep(15 * time.Second)
 			}
+			mlog.Warn("Failed to get posts batch for indexing. Retrying.", mlog.Err(err))
+
+			// Wait a bit before trying again.
+			time.Sleep(15 * time.Second)
 		}
 
 		tries++
@@ -443,12 +442,11 @@ func (worker *BleveIndexerWorker) IndexUsersBatch(progress IndexingProgress) (In
 		if usersBatch, err := worker.jobServer.Store.User().GetUsersBatchForIndexing(progress.LastEntityTime, endTime, BATCH_SIZE); err != nil {
 			if tries >= 10 {
 				return progress, model.NewAppError("IndexUsersBatch", "app.user.get_users_batch_for_indexing.get_users.app_error", nil, err.Error(), http.StatusInternalServerError)
-			} else {
-				mlog.Warn("Failed to get users batch for indexing. Retrying.", mlog.Err(err))
-
-				// Wait a bit before trying again.
-				time.Sleep(15 * time.Second)
 			}
+			mlog.Warn("Failed to get users batch for indexing. Retrying.", mlog.Err(err))
+
+			// Wait a bit before trying again.
+			time.Sleep(15 * time.Second)
 		} else {
 			users = usersBatch
 		}