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>

model/job.go

@@ -96,9 +96,8 @@ func JobFromJson(data io.Reader) *Job {
 	var job Job
 	if err := json.NewDecoder(data).Decode(&job); err == nil {
 		return &job
-	} else {
-		return nil
 	}
+	return nil
 }
 
 func JobsToJson(jobs []*Job) string {
@@ -110,9 +109,8 @@ func JobsFromJson(data io.Reader) []*Job {
 	var jobs []*Job
 	if err := json.NewDecoder(data).Decode(&jobs); err == nil {
 		return jobs
-	} else {
-		return nil
 	}
+	return nil
 }
 
 func (j *Job) DataToJson() string {