Potential leak of an object stored into "self"

1. By executing 314: _systemControl = [[CCEditBoxImplIOS_objc alloc] initWithFrame:rect editBox:this];
2. We entered to the function 67: -(id) initWithFrame: (CGRect) frameRect editBox: (void*) editBox
3. Then 69: "self = [super init];" returns object with +1 retain count
4. 93: "return nil" Potential leak of an object stored into "self".
Merge commit 'refs/pull/6197/head' of git://github.com/cocos2d/cocos2d-x into pull/6197
Remove unused comments in CCEditBoxImplIOS.mm
Merge pull request #6206 from dumganhar/pull/6197

Merge PR #6197: Potential leak in CCEditBoxImplIOS.mm