autotest: add a progress message for looking for a message in a log

Tools/autotest/common.py

@@ -8693,6 +8693,8 @@ switch value'''
                                         zero_time_base=True)
 
     def current_onboard_log_contains_message(self, messagetype):
+        self.progress("Checking (%s) for (%s)" %
+                      (self.current_onboard_log_filepath(), messagetype))
         dfreader = self.dfreader_for_current_onboard_log()
         m = dfreader.recv_match(type=messagetype)
         print("m=%s" % str(m))