[tempershow] Fix multi-ASIC: initialize global DB config for namespace resolution

On multi-ASIC platforms, SonicDBConfig.load_sonic_global_db_config()
must be called before creating namespace-scoped SonicV2Connector
instances. Without this, connect_to_all_dbs_for_ns() fails with
'validateNamespace: Initialize global DB config' and SFP temperatures
from per-ASIC namespace STATE_DBs are not displayed.

Add the standard isGlobalInit/load_sonic_global_db_config guard in
TemperShow.__init__(), matching the pattern used by fdbshow, fdbclear,
and nbrshow.

Signed-off-by: Vasundhara Volam <vvolam@microsoft.com>

Author: vvolam

scripts/tempershow

@@ -8,7 +8,7 @@ import json
 from datetime import datetime
 
 from tabulate import tabulate
-from swsscommon.swsscommon import SonicV2Connector
+from swsscommon.swsscommon import SonicDBConfig, SonicV2Connector
 from natsort import natsorted
 
 try:
@@ -67,6 +67,8 @@ NA = 'N/A'
 
 class TemperShow(object):
     def __init__(self):
+        if not SonicDBConfig.isGlobalInit():
+            SonicDBConfig.load_sonic_global_db_config()
         self.db = SonicV2Connector(host="127.0.0.1")
         self.db.connect(self.db.STATE_DB)
         self._sfp_helper_ready = self._init_sfp_util_helper()