Add a call to aom_clear_system_state()

Added aom_clear_system_state() in get_num_refs_to_disable
function before double operation.

Change-Id: Id1d1f340735a0a860b76d638fe8ca37d72cee036
diff --git a/av1/encoder/encodeframe_utils.h b/av1/encoder/encodeframe_utils.h
index d1146f5..82b3243 100644
--- a/av1/encoder/encodeframe_utils.h
+++ b/av1/encoder/encodeframe_utils.h
@@ -344,6 +344,7 @@
       else if (is_stat_consumption_stage_twopass(cpi)) {
         const FIRSTPASS_STATS *const this_frame_stats =
             read_one_frame_stats(&cpi->twopass, cur_frame_display_index);
+        aom_clear_system_state();
         const double coded_error_per_mb =
             this_frame_stats->coded_error / cpi->frame_info.num_mbs;
         // Disable LAST2_FRAME if the coded error of the current frame based on