qa/364 - update _filter_linux function
qa/364 - update _filter_linux function

A variety network.sockstat.* metrics return errors, filter them out.

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp