i965: Remove dead field brw_wm_prog_data::error.

src/mesa/drivers/dri/i965/brw_context.h

@@ -301,7 +301,6 @@ struct brw_wm_prog_data {
 
    GLuint nr_params;       /**< number of float params/constants */
    GLuint nr_pull_params;
-   bool error;
    bool dual_src_blend;
    int dispatch_width;
    uint32_t prog_offset_16;