Fix some minor gofmt and golint issues

[afbjorklund]

So that "make gofmt" and "make golint" go green again

See https://goreportcard.com/report/github.com/kubernetes/minikube

[RA489]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: afbjorklund, RA489

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [RA489,afbjorklund]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[codecov-io]

Codecov Report

Merging #8145 into master will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##           master    #8145   +/-   ##
=======================================
  Coverage   35.27%   35.27%           
=======================================
  Files         146      146           
  Lines        9326     9326           
=======================================
  Hits         3290     3290           
  Misses       5637     5637           
  Partials      399      399           

Impacted Files	Coverage Δ
cmd/minikube/cmd/start_flags.go	50.97% <0.00%> (ø)
pkg/minikube/perf/binary.go	78.94% <ø> (ø)