fix the strange behavior when repeat CCJumpTo

fix the strange behavior when using CCRepeat 1< times run with CCJumpTo.

this problem is refered to by [Bug #1525](http://www.cocos2d-x.org/issues/1525).

for example,

```
m_tamara->setPosition( ccp(100,70) );

CCActionInterval* actionTo1 = CCJumpTo::create(2, ccp(m_tamara->getPositionX() + 40, m_tamara->getPositionY()), 2, 1);
CCActionInterval* actionTo2 = CCJumpTo::create(2, ccp(m_tamara->getPositionX() - 40, m_tamara->getPositionY()), 2, 1);
CCActionInterval* actionTo3 = CCSequence::create(actionTo1, actionTo2, NULL);
CCActionInterval* actionTo = CCRepeatForever::create(actionTo3);

m_tamara->runAction( actionTo);
```

first iteration is ok. when the second iteration, the sprite moves unexpected way.