address minor bugs in nxos shared module
address minor bugs in nxos shared module

This addresses two issues with the nxos shared module.  The first issue is
argument precedence checking.  The module should prefer explicit arguments
over arguments passed vi the provider.  This is now fixed to honor that
precedence.  The second issue is collecting output from nxapi and returning
the response.  Prior to this change the entire json structure was returned.
Now just the output is returned to align it better with cli based output

thaim/ansible,thaim/ansible