In OpenRC exec module, make sure to ignore retcode on status

[jfindlay]

What does this PR do?

In the OpenRC exec module, make sure to ignore retcode on status.

What issues does this PR fix or reference?

For example, when a service is stopped, the retcode of /sbin/openrc-run status is
3, not 0.

Previous Behavior

# salt-call --local state.single service.dead my-service
[ERROR   ] Command '/etc/init.d/my-service status' failed with return code: 3
[ERROR   ] output:  * status: stopped
local:
----------
          ID: my-service
    Function: service.dead
      Result: True
     Comment: The service my-service is already dead
     Started: 05:46:06.918276
    Duration: 235.749 ms
     Changes:

Summary for local
------------
Succeeded: 1
Failed:    0
------------
Total states run:     1
Total run time: 235.749 ms

New Behavior

# salt-call --local state.single service.dead my-service
local:
----------
          ID: my-service
    Function: service.dead
      Result: True
     Comment: The service my-service is already dead
     Started: 05:46:31.445100
    Duration: 233.924 ms
     Changes:

Summary for local
------------
Succeeded: 1
Failed:    0
------------
Total states run:     1
Total run time: 233.924 ms

Tests written?

Yes

Commits signed with GPG?

Yes