Fix Fl_{Wayland|Xlib}_{Copy|Image}_Surface_Driver::set_current()

Member function Fl_Cairo_Graphics_Driver::set_cairo() needs be called only to initialize the driver.
Doing it also later undoes the effect of Fl_Widget_Surface::translate() if used
when Fl_Surface_Device::pop_current() calls the overridden Fl_Surface_Device::set_current().