To me, doesn't sound like it will be a problem. The Chinese tend to be suspicious mostly of big professional video cams like you see TV cameramen use since that's the hallmark of the dreaded foreign snoop...oops I mean journalist. It's not usual for incoming foreigners to get stopped going through Customs anyway, and you don't have to declare personal goods anymore on a Customs form. But if by odd chance they do want a look and question you, just tell them you are two tourists sharing one combined bag for both your gear. This isn't a big deal.