[Namespace]: Remove key exists check in dbs_get_all

to reduce time taken.

Signed-off-by: SuvarnaMeenakshi <sumeenak@microsoft.com>

src/sonic_ax_impl/mibs/__init__.py

@@ -552,12 +552,16 @@ def dbs_get_all(dbs, db_name, _hash, *args, **kwargs):
  db get_all function executed on global and all namespace DBs.
  """
  result = {}
+ Namespace.connect_all_dbs(dbs, db_name)
+ if len(dbs) == 1:
+ return dbs[0].get_all(db_name, _hash, *args, **kwargs)
  for db_conn in dbs:
- db_conn.connect(db_name)
- if(db_conn.exists(db_name, _hash)):
- ns_result = db_conn.get_all(db_name, _hash, *args, **kwargs)
- if ns_result is not None:
- result.update(ns_result)
+ # If there are multiple namespaces, _hash might not be 
+ # present in all namespace, ignore if not present in a
+ # specfic namespace.
+ ns_result = db_conn.get_all(db_name, _hash, blocking=False)
+ if ns_result is not None:
+ result.update(ns_result)
  return result
 
  @staticmethod