compositor-drm: cast surface to EGLNativeWindowType

gl_renderer_output_create expects `window_for_legacy' variable to be of
type EGLNativeWindowType, not EGLNativeDisplayType. This variable is
used later in eglCreateWindowSurface().

Signed-off-by: Dawid Gajownik <gajownik@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

src/compositor-drm.c

@@ -1828,7 +1828,7 @@ drm_output_init_egl(struct drm_output *output, struct drm_backend *b)
 	if (format[1])
 		n_formats = 2;
 	if (gl_renderer->output_create(&output->base,
-				       (EGLNativeDisplayType)output->surface,
+				       (EGLNativeWindowType)output->surface,
 				       output->surface,
 				       gl_renderer->opaque_attribs,
 				       format,