print skipped file names to stdout

Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
diff --git a/scripts/code_style.py b/scripts/code_style.py
index 61b1ab0..85008be 100755
--- a/scripts/code_style.py
+++ b/scripts/code_style.py
@@ -33,15 +33,12 @@
 def print_err(*args):
     print("Error: ", *args, file=sys.stderr)
 
-def print_warn(*args):
-    print("Warn:", *args, file=sys.stderr)
-
 # Print the file names that will be skipped and the help message
 def print_skip(files_to_skip):
     print()
     print(*files_to_skip, sep=", SKIP\n", end=", SKIP\n")
-    print_warn("The listed files will be skipped because\n"
-               "they are not included in the default list.")
+    print("Warn: The listed files will be skipped because\n"
+          "they are not included in the default list.")
     print()
 
 # Match FILENAME(s) in "check SCRIPT (FILENAME...)"