GOLANG: Syntax formatting with gofmt

Use the gofmt command to reformat golang sources gathered outside the vendor/ directory.

Golang source formatting
% git clone ssh://gerrit.opencord.org:29418/voltha-lib-go.git
% cd voltha-lib-go

% make sterile
% make golang-fmt

% find . ! -path './vendor/\*' -name '*.go' -print | xargs -n1 gofmt -s -e -w