Fix CI failure

Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
diff --git a/scripts/code_style.py b/scripts/code_style.py
index e40a20c..c31fb29 100755
--- a/scripts/code_style.py
+++ b/scripts/code_style.py
@@ -202,7 +202,7 @@
         if skip_src_files:
             print_skip(skip_src_files)
     else:
-        src_files = covered
+        src_files = list(covered)
 
     if args.fix:
         # Fix mode