when making objlist files, encode string to utf-8 before trying to hash it.

RELNOTES: None.
PiperOrigin-RevId: 166215349
diff --git a/tools/objc/make_hashed_objlist.py b/tools/objc/make_hashed_objlist.py
index 077d2d1..85daeb6 100644
--- a/tools/objc/make_hashed_objlist.py
+++ b/tools/objc/make_hashed_objlist.py
@@ -36,7 +36,7 @@
     obj_file_path = line.rstrip('\n')
     hashed_obj_file_path = '%s_%s.o' % (
         os.path.splitext(obj_file_path)[0],
-        hashlib.md5(obj_file_path).hexdigest())
+        hashlib.md5(obj_file_path.encode('utf-8')).hexdigest())
 
     hashed_obj_file_list.write(hashed_obj_file_path + '\n')