run-drc-for-cell-gds-using-magic: Better ignored output.

Make an ignored error clear by using a black tick and adding message.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>
diff --git a/run-drc-for-cell-gds-using-magic/run_all_drc.py b/run-drc-for-cell-gds-using-magic/run_all_drc.py
index 7ca18bb..8af9bc2 100644
--- a/run-drc-for-cell-gds-using-magic/run_all_drc.py
+++ b/run-drc-for-cell-gds-using-magic/run_all_drc.py
@@ -204,8 +204,13 @@
             total += 1
             cell_name, errors = future.result()
 
-            symbol = "❌"
-            message = "ERROR"
+            if cell_name in known_bad_list:
+                symbol = "✘\ufe0f"
+                message = "ERROR (ignored as known bad)"
+            else:
+                symbol = "❌"
+                message = "ERROR"
+
             if len(errors) == 0:
                 successes += 1
                 # This tick is rendered black on all major platforms except for