Fix a potential assertion failure

Change-Id: I24d129aceb66e00388bedf98bc8e46524c0812eb

av1/common/seg_common.c

@@ -46,10 +46,11 @@ int av1_is_segfeature_signed(SEG_LVL_FEATURES feature_id) {
 
 void av1_set_segdata(struct segmentation *seg, int segment_id,
                      SEG_LVL_FEATURES feature_id, int seg_data) {
-  assert(seg_data <= seg_feature_data_max[feature_id]);
   if (seg_data < 0) {
     assert(seg_feature_data_signed[feature_id]);
     assert(-seg_data <= seg_feature_data_max[feature_id]);
+  } else {
+    assert(seg_data <= seg_feature_data_max[feature_id]);
   }
 
   seg->feature_data[segment_id][feature_id] = seg_data;