Get _log_sanity_results value for all loggers

Author: ekouts

reframe/core/logging.py

@@ -940,7 +940,7 @@ def log_performance(self, level, task, msg=None, multiline=False):
         if (
             self.check is None or
             not self.check.is_performance_check() and
-            not self.logger._log_sanity_results
+            not getattr(self.logger, '_log_sanity_results', False)
         ):
             return