[3.10] gh-99811: Use correct variable to search for time in format string (GH-99812) (GH-99852)

(cherry picked from commit 1d1bb95)
Co-authored-by: cemysce <[email protected]>

Author: miss-islington

Lib/logging/__init__.py

@@ -487,7 +487,7 @@ def __init__(self, *args, **kwargs):
 
     def usesTime(self):
         fmt = self._fmt
-        return fmt.find('$asctime') >= 0 or fmt.find(self.asctime_format) >= 0
+        return fmt.find('$asctime') >= 0 or fmt.find(self.asctime_search) >= 0
 
     def validate(self):
         pattern = Template.pattern