public function setgo(Request $request){
        //验证
        $this->validate(request(),[
            'name'=>'required|min:3',
        ]);
        //逻辑
        $name=request('name');
        $user=\Auth::user();
        if($user!=$user->name){
            if(User::where('name',$name)->count()>0){
                return back()->withErrors("用户名已经被注册 ");
            }
            $user->name=name;
            if($request->file('touxiang')){
                $path=$request->file('touxiang')->sctorePublicly($user->id);
                $user->touxiang="/storage/".$path;
            }
            $user->save();
            return back();
        }
    }

照着老师的都写完了，但我要是不想改名字只想改头像怎么办呢？因为名字不变的话，会提示用户名已经注册，就改不了了呀