Fix kaggle submission format in format_lines()

Author: voilin

inference.py

@@ -83,7 +83,7 @@ def format_lines(video_ids, predictions, top_k):
             for class_index in top_indices]
     line = sorted(line, key=lambda p: -p[1])
     yield video_ids[video_index].decode('utf-8') + "," + " ".join(
-        "%i:%g" % (label, score) for (label, score) in line) + "\n"
+        "%i %g" % (label, score) for (label, score) in line) + "\n"
 
 
 def get_input_data_tensors(reader, data_pattern, batch_size, num_readers=1):