Cannot exclude test files when using errcheck

[alaypatel07]

1. Version of golangci-lint: golangci-lint --version (or git commit if you don't use binary distribution)
   Commit: de1d1ad
2. Config file: cat /tmp/.golangci-lint-config.yml

linters-settings:
  linters-settings:
    errcheck:
      without_tests: true
  dupl:
    threshold: 400
    min-len: 3
  lll:
    line-length: 170
    tab-width: 1'

3. Go environment: go version && go env

GOARCH="amd64"
GOBIN=""
GOCACHE="/root/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/go"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build208835018=/tmp/go-build -gno-record-gcc-switches"

4. Verbose output of running:

able=varcheck --enable=goconst --enable=unparam --enable=ineffassign --enable=nakedret --enable=inter
facer --enable=misspell --enable=gocyclo --enable=lll --enable=dupl --skip-dirs=atomic --enable=goimp
orts ./pkg/... ./examples/... .
pkg/builder/builder_suite_test.go:69:14: Error return value of `testenv.Stop` is not checked (errchec
k)
        testenv.Stop()
                    ^
pkg/cache/cache_suite_test.go:56:14: Error return value of `testenv.Stop` is not checked (errcheck)
        testenv.Stop()
                    ^
pkg/cache/cache_test.go:404:28: Error return value of `kscheme.Scheme.Convert` is not checked (errche
ck)
                                        kscheme.Scheme.Convert(knownPod2, uKnownPod2, nil)
                                                              ^
pkg/client/client_suite_test.go:57:14: Error return value of `testenv.Stop` is not checked (errcheck)
        testenv.Stop()
                    ^
pkg/client/client_test.go:300:19: Error return value of `scheme.Convert` is not checked (errcheck)
                                scheme.Convert(dep, u, nil)
                                              ^
pkg/client/client_test.go:324:19: Error return value of `scheme.Convert` is not checked (errcheck)
                                scheme.Convert(node, u, nil)
                                              ^
pkg/client/client_test.go:339:19: Error return value of `scheme.Convert` is not checked (errcheck)
                                scheme.Convert(actual, au, nil)
                                              ^
pkg/client/client_test.go:2169:15: Error return value of `dReader.Get` is not checked (errcheck)
                        dReader.Get(context.TODO(), key, &actual)
                                   ^
pkg/client/client_test.go:2182:15: Error return value of `dReader.Get` is not checked (errcheck)
                        dReader.Get(context.TODO(), key, &actual)

There is a parameter for excluding tests but it is not being used here