Refactor error handling (#308)

use fmt instead of log

log.Fatal -> return err

set non-zero exit code on error

print to default err log

cleanup

fix vet

Co-authored-by: Norwin Roosen <git@nroo.de>
Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://gitea.com/gitea/tea/pulls/308
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: 6543 <6543@obermui.de>
Co-Authored-By: Norwin <noerw@noreply.gitea.io>
Co-Committed-By: Norwin <noerw@noreply.gitea.io>

cmd/times/add.go

@@ -6,7 +6,6 @@ package times
 
 import (
 	"fmt"
-	"log"
 	"strings"
 	"time"
 
@@ -41,20 +40,16 @@ func runTrackedTimesAdd(cmd *cli.Context) error {
 
 	issue, err := utils.ArgToIndex(ctx.Args().First())
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 
 	duration, err := time.ParseDuration(strings.Join(ctx.Args().Tail(), ""))
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 
 	_, _, err = ctx.Login.Client().AddTime(ctx.Owner, ctx.Repo, issue, gitea.AddTimeOption{
 		Time: int64(duration.Seconds()),
 	})
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	return nil
+	return err
 }