[202012] [pfcwd] Fix the return code in invalid case (#1698)

Backport #1691
- What I did
Set the correct return code when pfcwd command is specified with invalid options

Signed-off-by: Neetha John <nejo@microsoft.com>

pfcwd/main.py

@@ -244,7 +244,7 @@ def start(self, action, restoration_time, ports, detection_time):
             click.echo("Failed to run command, invalid options:")
             for opt in invalid_ports:
                 click.echo(opt)
-            exit()
+            exit(1)
         self.start_cmd(action, restoration_time, ports, detection_time)
 
 

tests/pfcwd_test.py

@@ -255,7 +255,7 @@ def test_pfcwd_start_ports_invalid(self):
             obj=db
         )
         print(result.output)
-        assert result.exit_code == 0
+        assert result.exit_code == 1
         assert result.output == pfcwd_show_start_config_output_fail
 
     @classmethod
@@ -447,7 +447,7 @@ def test_pfcwd_start_ports_masic_invalid(self):
             obj=db
         )
         print(result.output)
-        assert result.exit_code == 0
+        assert result.exit_code == 1
         assert result.output == show_pfc_config_start_fail
 
         # get config after the command, config shouldn't change