code_size_compare: print 'None' if comparing size for a new file

Signed-off-by: Yanray Wang <yanray.wang@arm.com>
diff --git a/scripts/code_size_compare.py b/scripts/code_size_compare.py
index b886a9e..e79b379 100755
--- a/scripts/code_size_compare.py
+++ b/scripts/code_size_compare.py
@@ -647,9 +647,11 @@
                             "{:.2%}".format(text_vari[3]) + ","
                             + "{:.2%}".format(data_vari[3])))
             else:
-                output.write("{:<30} {:<18}\n"
-                             .format(fname,
-                                     str(text_vari[0]) + "," + str(data_vari[0])))
+                output.write(
+                    format_string
+                    .format(fname,
+                            str(text_vari[0]) + "," + str(data_vari[0]),
+                            'None', 'None', 'None'))
 
 
 class CodeSizeComparison: