BERLIN, Oct 9 (Reuters) - Tesla is worried that it won"t be able to hire enough people to staff its new factory near Berlin, Chief Executive Elon Musk said at a festival held on the site of the new plant on Saturday, according to a live stream on social media. Musk, who also said that he hoped the plant would in future build Tesla"s planned trucks, added that he hoped staff would come from all over Europe to work there. "We"re a bit worried we wont be able to find enough people. We really need great talent to come here from all over Europe," he said.