Fix QCameraInfo to be invalid if camera failed to find device

Since QCameraInfo uses deviceControl and infoControl to get info about
camera, it needs to clear these controls if the camera failed to find
a device by name.

Change-Id: I1404f70234f978fa4568b6c883a5676f61e08145
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
(cherry picked from commit 42932e1a)