egl: only store device name when Wayland support is built

The device name is only needed for WL_bind_wayland_display so make this clear
by only storing the device name when Wayland support is built.

Signed-off-by: Frank Binns <frank.binns@imgtec.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index 19f54de..859612f 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -858,9 +858,12 @@
       close(dri2_dpy->fd);
    if (dri2_dpy->driver)
       dlclose(dri2_dpy->driver);
-   free(dri2_dpy->device_name);
    free(dri2_dpy->driver_name);
 
+#ifdef HAVE_WAYLAND_PLATFORM
+   free(dri2_dpy->device_name);
+#endif
+
    switch (disp->Platform) {
 #ifdef HAVE_X11_PLATFORM
    case _EGL_PLATFORM_X11: