Modify comments to make them more inclusive

Signed-off-by: Aditya Deshpande <aditya.deshpande@arm.com>
diff --git a/tests/scripts/check_files.py b/tests/scripts/check_files.py
index 33b15ac..fa7b8c0 100755
--- a/tests/scripts/check_files.py
+++ b/tests/scripts/check_files.py
@@ -268,7 +268,7 @@
 
     heading = "Invalid UTF-8 or forbidden character:"
 
-    # Only allow valid UTF-8, and only white-listed characters.
+    # Only allow valid UTF-8, and only other explicitly allowed characters.
     # We deliberately exclude all characters that aren't a simple non-blank,
     # non-zero-width glyph, apart from a very small set (tab, ordinary space,
     # line breaks, "basic" no-break space and soft hyphen). In particular,