chore: remove default values assignment in NewWaitGroupContext (#15)

Author: reugn

wait_group_context.go

@@ -20,10 +20,8 @@ type WaitGroupContext struct {
 // NewWaitGroupContext returns a new WaitGroupContext with Context ctx.
 func NewWaitGroupContext(ctx context.Context) *WaitGroupContext {
 return &WaitGroupContext{
-ctx: ctx,
-done: make(chan struct{}),
-counter: 0,
-state: 0,
+ctx: ctx,
+done: make(chan struct{}),
 }
 }