Fixed file_path error

Author: ZacJW

inline-css.py

@@ -10,7 +10,7 @@
 for file_path_str in FILES_LIST:
     file_path_list = REPO_PATH.glob(file_path_str)
     for file_path in file_path_list:
-        with open(file_path_list, 'r') as file:
+        with open(file_path, 'r') as file:
             html = pm.transform(file.read())
-        with open(file_path_list, 'w') as file:
+        with open(file_path, 'w') as file:
             file.write(html)