Fix: Add check in floor1_info_unpack

Add check for rangebits set by oggpack_read().

Bug: 155560008
Test: poc in bug

Change-Id: I7bd1ea124eca9670cc56fe1d4fc255a281527105
diff --git a/Tremolo/floor1.c b/Tremolo/floor1.c
index 7811aba..1a920a7 100644
--- a/Tremolo/floor1.c
+++ b/Tremolo/floor1.c
@@ -140,6 +140,7 @@
   /* read the post list */
   info->mult=oggpack_read(opb,2)+1;     /* only 1,2,3,4 legal now */
   rangebits=oggpack_read(opb,4);
+  if(rangebits < 0) goto err_out;
 
   for(j=0,k=0;j<info->partitions;j++)
     count+=info->klass[info->partitionclass[j]].class_dim;