fixes a number of issues with nxos_facts (#22923)

* updates command runs to return warning if command fails
* fixes variable issues from recent refactoring
* removes provider from return of module

lib/ansible/module_utils/nxos.py

@@ -50,7 +50,7 @@ nxos_argument_spec = {
     'validate_certs': dict(type='bool'),
     'timeout': dict(type='int'),
 
-    'provider': dict(type='dict', no_log=True),
+    'provider': dict(type='dict'),
     'transport': dict(choices=['cli', 'nxapi'])
 }