Bug 497199 - Skip dirsync if disconnected during incremental update
    
    If some sort of error occurs during the sending updates to AD phase
    of an incremental winsync update, we still attempt to send the dirsync
    control to AD.  This can cause spurious error messages to be logged to
    the errors log stating that we can't send the control since we are not
    connected to AD anymore.
    
    This patch simply skips sending the dirsync control if we encountered
    an error sending updates to AD.