bug: Use evalSymlinks to replace filepath.EvalSymlinks

[Xuanwo]

go-service-fs/utils.go

Lines 69 to 83 in f60980c

	if opt.HasWorkDir {
	workDir, err := filepath.EvalSymlinks(opt.WorkDir)
	if err != nil {
	return nil, err
	}
	store.workDir = workDir
	}
	// Check and create work dir
	err = os.MkdirAll(store.workDir, 0755)
	if err != nil {
	return nil, err
	}
	return
	}

Current logic will lead to NewStorager return object not exist error like https://github.com/beyondstorage/beyond-tp/pull/167/checks?check_run_id=3649077637

2021-09-20T07:30:23.817Z	ERROR	task/staff.go:151	format storage	{"error": "fs new_storager: [work_dir: /tmp/b/]: object not exist: lstat /tmp/b: no such file or directory"}
github.com/beyondstorage/beyond-tp/task.(*Staff).Start
	/home/runner/work/beyond-tp/beyond-tp/task/staff.go:151

We need to handle this.

Fix

• Use evalSymlinks to replace filepath.EvalSymlinks

[Xuanwo]

ping @1445601153 for a fix.