Fixed build error.
Fixed build error.

dc1394 is a live camera stream and does not take a file name.

mathstuf/sprokit,Kitware/sprokit,linus-sherrill/sprokit,linus-sherrill/sprokit,mathstuf/sprokit,mathstuf/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,Kitware/sprokit,Kitware/sprokit,Kitware/sprokit,linus-sherrill/sprokit