st/mesa: invalidate the readpix cache in st_indirect_draw_vbo

Cc: <mesa-stable@lists.freedesktop.org>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/state_tracker/st_draw.c

@@ -274,6 +274,8 @@ st_indirect_draw_vbo(struct gl_context *ctx,
    assert(ctx->NewState == 0x0);
    assert(stride);
 
+   st_invalidate_readpix_cache(st);
+
    /* Validate state. */
    if ((st->dirty | ctx->NewDriverState) & ST_PIPELINE_RENDER_STATE_MASK ||
        st->gfx_shaders_may_be_dirty) {