Fix potential float overflow in ml_predict_tx_split()

Change-Id: Ia23b5667dfe729285324411c7e1fb06d7cde5785

av1/encoder/rdopt.c

diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index bdfc8c8..a01bd3a 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -4145,6 +4145,8 @@
 
   float score = 0.0f;
   av1_nn_predict(features, nn_config, &score);
+  if (score > 8.0f) return 100;
+  if (score < -8.0f) return 0;
   score = 1.0f / (1.0f + (float)exp(-score));
   return (int)(score * 100);
 }