[X11] Fix up compilation when EGL headers are not present.

src/video/x11/SDL_x11window.c

@@ -563,6 +563,7 @@ X11_CreateWindow(_THIS, SDL_Window * window)
         && ( !_this->gl_data || ! _this->gl_data->HAS_GLX_EXT_create_context_es2_profile )
 #endif  
     ) {
+#if SDL_VIDEO_OPENGL_EGL  
         if (!_this->egl_data) {
             X11_XDestroyWindow(display, w);
             return -1;
@@ -575,6 +576,9 @@ X11_CreateWindow(_THIS, SDL_Window * window)
             X11_XDestroyWindow(display, w);
             return SDL_SetError("Could not create GLES window surface");
         }
+#else
+        return SDL_SetError("Could not create GLES window surface (no EGL support available)");
+#endif /* SDL_VIDEO_OPENGL_EGL */
     }
 #endif