Fix a flake8 warning

Author: tk0miya

sphinx/util/logging.py

@@ -369,9 +369,10 @@ def is_suppressed_warning(type: str, subtype: str, suppress_warnings: List[str])
             target, subtarget = warning_type, None
 
         if target == type:
-            if (subtype is None and subtarget is None
-               or subtarget is None or
-               subtarget == subtype or subtarget == '*'):
+            if ((subtype is None and subtarget is None) or
+                    subtarget is None or
+                    subtarget == subtype or
+                    subtarget == '*'):
                 return True
 
     return False