[ycabled] Fix some syntax warnings in ycabled (sonic-net#263)

This PR fixes some syntax warnings for ycabled.

Signed-off-by: vaibhav-dahiya vdahiya@microsoft.com

Description
Motivation and Context
remove some syntax warnings

How Has This Been Tested?
UT coverage would test the change

Signed-off-by: vaibhav-dahiya <vdahiya@microsoft.com>

sonic-ycabled/ycable/ycable_utilities/y_cable_helper.py

@@ -1526,7 +1526,7 @@ def post_port_mux_info_to_db(logical_port_name, table):
         else:
             mux_info_dict = get_muxcable_info(physical_port, logical_port_name)
 
-        if mux_info_dict is not None and mux_info_dict is not -1:
+        if mux_info_dict is not None and mux_info_dict != -1:
             #transceiver_dict[physical_port] = port_info_dict
             fvs = swsscommon.FieldValuePairs(
                 [('tor_active',  mux_info_dict["tor_active"]),
@@ -1583,7 +1583,7 @@ def post_port_mux_static_info_to_db(logical_port_name, static_table):
             mux_static_info_dict = get_muxcable_static_info(physical_port, logical_port_name)
 
 
-        if mux_static_info_dict is not None and mux_static_info_dict is not -1:
+        if mux_static_info_dict is not None and mux_static_info_dict != -1:
             #transceiver_dict[physical_port] = port_info_dict
             fvs = swsscommon.FieldValuePairs(
                 [('read_side',  mux_static_info_dict["read_side"]),
@@ -2866,7 +2866,7 @@ def task_cli_worker(self):
                 helper_logger.log_notice("Y_CABLE_DEBUG: trying to enable/disable debug logs")
                 if fvp_m:
 
-                    if key is "Y_CABLE":
+                    if key == "Y_CABLE":
                         continue
 
                     fvp_dict = dict(fvp_m)