egl/android: Remove unused variables

There are some unused variables left after previous clean-ups triggering
compiler warnings. Let's remove them.

Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

src/egl/drivers/dri2/platform_android.c

@@ -431,10 +431,8 @@ droid_image_get_buffers(__DRIdrawable *driDrawable,
 static EGLBoolean
 droid_swap_buffers(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *draw)
 {
-   struct dri2_egl_driver *dri2_drv = dri2_egl_driver(drv);
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
    struct dri2_egl_surface *dri2_surf = dri2_egl_surface(draw);
-   _EGLContext *ctx;
 
    if (dri2_surf->base.Type != EGL_WINDOW_BIT)
       return EGL_TRUE;