[xcvrd] silence port update event warnings (PR sonic-net#567)

Warnings should only be used to alert an administrator that something
could cause issues.  Typically warnings will be evaluated by an
administrator as tagged by their SIEM, so it makes sense to reduce the
workload by not incorrectly tagging these log messages.

Reduced the log level to NOTICE which will still appear at the default
log levels in case anyone is parsing these events in their SIEM.

Signed-off-by: Brad House (@bradh352)

sonic-xcvrd/xcvrd/xcvrd_utilities/port_event_helper.py

@@ -102,7 +102,7 @@ def subscribe_port_update_event(self):
                 port_tbl.filter = d['FILTER'] if 'FILTER' in d else None
                 asic_context[port_tbl] = asic_id
                 sel.addSelectable(port_tbl)
-                self.logger.log_warning("subscribing to port_tbl {} - {} DB of namespace {} ".format(
+                self.logger.log_notice("subscribing to port_tbl {} - {} DB of namespace {} ".format(
                                             port_tbl, list(d.values())[0], namespace))
         self.sel, self.asic_context = sel, asic_context
 
@@ -144,7 +144,7 @@ def handle_port_update_event(self):
                     if not multi_asic.is_front_panel_port(port_name, role):
                         continue
 
-                    self.logger.log_warning("$$$ {} handle_port_update_event() : op={} DB:{} Table:{} fvp {}".format(
+                    self.logger.log_notice("$$$ {} handle_port_update_event() : op={} DB:{} Table:{} fvp {}".format(
                                                             port_name, op, port_tbl.db_name, port_tbl.table_name, fvp))
                     if 'index' not in fvp:
                        fvp['index'] = '-1'
@@ -193,7 +193,7 @@ def handle_port_update_event(self):
                                                             db_name,
                                                             table_name)
                 # This is the final event considered for processing
-                self.logger.log_warning("*** {} handle_port_update_event() fvp {}".format(
+                self.logger.log_notice("*** {} handle_port_update_event() fvp {}".format(
                     key, fvp))
                 if port_change_event is not None:
                     has_event = True