fix make extract
fix make extract

> err_map.go is not gone, it was just renamed in a recent refactor:
> https://github.com/kubernetes/minikube/blob/master/pkg/minikube/reason/known_issues.go

$ make extract
go run cmd/extract/extract.go
panic: err_map.go doesn't exist

goroutine 1 [running]:
main.main()
	/home/lizj/workspace/k8s/minikube/cmd/extract/extract.go:47 +0x1b4
exit status 2
Makefile:304: recipe for target 'extract' failed
make: *** [extract] Error 1

Fixes #9126
Signed-off-by: Li Zhijian <77612007ee711fb02c065264d15511c027ff1ff7@cn.fujitsu.com>

kubernetes/minikube,kubernetes/minikube,dalehamel/minikube,kubernetes/minikube,warmchang/minikube,warmchang/minikube,dalehamel/minikube,kubernetes/minikube,kubernetes/minikube,warmchang/minikube,kubernetes/minikube,kubernetes/minikube,warmchang/minikube,warmchang/minikube,warmchang/minikube,dalehamel/minikube,warmchang/minikube