Coverity (CID 22275) pointed out it wasn't initialized in the
constructor.  It isn't even accessed; and the method that sets it
claims the parameter it sets it to is unused.  So just remove it.

Change-Id: Id48f45a89b7a2d3d44e92b785d425592f1bc6467
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>