[reSIProcate] Possible issue in AresDnsPollItem

["Dario Bozzali" <Dario.Bozzali@xxxxxxxxxxx>]

Title: Possible issue in AresDnsPollItem

Hi all,

I'm using the latest revision of Resiprocate mainline (10976) and I noticed a possible issue in AresDnsPollItem class, in particular in resetPollGrp() method.
In my opinion it could happen that mPollGrp is NULL, so we should check it (same check is done in several other places in the code, for example in AresDns).
In detail
    if (mPollGrp) {
        mPollGrp->delPollItem(mPollHandle);
    }
instead of
    mPollGrp->delPollItem(mPollHandle);

Best regards,
Dario.