avcodec/hevc_ps: More complete window reset

Fixes out of array read
Fixes: signal_sigsegv_35bcf26_471_cov_2806540268_CAINIT_A_SHARP_4.bit
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 57e5812198)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/hevc_ps.c

@@ -1030,10 +1030,8 @@ int ff_hevc_decode_nal_sps(HEVCContext *s)
         }
         av_log(s->avctx, AV_LOG_WARNING,
                "Displaying the whole video surface.\n");
-        sps->pic_conf_win.left_offset   =
-        sps->pic_conf_win.right_offset  =
-        sps->pic_conf_win.top_offset    =
-        sps->pic_conf_win.bottom_offset = 0;
+        memset(&sps->pic_conf_win, 0, sizeof(sps->pic_conf_win));
+        memset(&sps->output_window, 0, sizeof(sps->output_window));
         sps->output_width               = sps->width;
         sps->output_height              = sps->height;
     }