fix decode_combin_test.sh

Author: LvHang

egs/wsj/s5/steps/decode_combine_test.sh

@@ -30,7 +30,7 @@ echo "$0 $@"  # Print the command line for logging
 [ -f ./path.sh ] && . ./path.sh; # source the path.
 . parse_options.sh || exit 1;
 
-if [ $# != 5 ]; then
+if [ $# != 3 ]; then
    echo "Usage: steps/decode_combine_test.sh [options] <graph-dir> <data-dir> <decode-dir>"
    echo "... where <decode-dir> is assumed to be a sub-directory of the directory"
    echo " where the model is."