[damned-lies] Removed unneeded lines in source_files()

[Claude Paroz <claudep src gnome org>]

commit b8ab533afa384853f6cfafee852de3030378897e
Author: Claude Paroz <claude 2xlibre net>
Date:   Sun Jun 24 22:39:24 2018 +0200

    Removed unneeded lines in source_files()

 stats/utils.py | 2 --
 1 file changed, 2 deletions(-)
---
diff --git a/stats/utils.py b/stats/utils.py
index 39d6cb29..1676cee0 100644
--- a/stats/utils.py
+++ b/stats/utils.py
@@ -97,8 +97,6 @@ class DocFormat:
         if not source_list and self.format == 'mallard':
             # Fallback to directory listing
             return [f for f in self.list_C_files() if f.suffix == '.page']
-        elif source_list is None:
-            return sources
         if isinstance(source_list, str):
             sources += source_list.split()
         return [Path('C', src) for src in sources if src not in ('', '$(NULL)')]