retrieve virtual switch name from driver object directly

[sharifelgamal]

RawDriver is never being populated anymore by non-legacy drivers, and we never noticed because this code was not called by anything but mount. This is fixed by addressing a long-standing TODO and just grab the wanted value directly from the object instead of counting on RawDriver.

Before

* minikube v1.10.0 on Microsoft Windows 10 Pro 10.0.18363 Build 18363
* Automatically selected the hyperv driver. Other choices: docker, virtualbox
* Starting control plane node minikube in cluster minikube
* Creating hyperv VM (CPUs=2, Memory=6000MB, Disk=20000MB) ...
* Preparing Kubernetes v1.18.1 on Docker 19.03.8 ...
panic: runtime error: index out of range [1] with length 0

goroutine 1 [running]:
k8s.io/minikube/pkg/minikube/cluster.HostIP(0xc000a0c240, 0x7, 0x1df4d40, 0xc0004cfcb0, 0x0, 0xc000782690)
        C:/Users/shari/Documents/minikube/pkg/minikube/cluster/ip.go:46 +0xcd5
k8s.io/minikube/pkg/minikube/node.Start(0x1dc3d20, 0xc00059a0a0, 0x0, 0x1de35a0, 0xc0005aa380, 0xc000a0c240, 0xc0003e6e00, 0xc0005aa280, 0xc000535aa0, 0x4e01, ...)
        C:/Users/shari/Documents/minikube/pkg/minikube/node/start.go:93 +0x201
k8s.io/minikube/cmd/minikube/cmd.startWithDriver(0x1dc3d20, 0xc00059a0a0, 0x0, 0x1de35a0, 0xc0005aa380, 0xc000a0c240, 0xc0003e6e00, 0xc0005aa280, 0xc000535aa0, 0x0, ...)
        C:/Users/shari/Documents/minikube/cmd/minikube/cmd/start.go:281 +0x83
k8s.io/minikube/cmd/minikube/cmd.runStart(0x2ac7c40, 0x2b13d10, 0x0, 0x0)
        C:/Users/shari/Documents/minikube/cmd/minikube/cmd/start.go:202 +0x6f3
github.com/spf13/cobra.(*Command).execute(0x2ac7c40, 0x2b13d10, 0x0, 0x0, 0x2ac7c40, 0x2b13d10)
        C:/Users/shari/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:846 +0x2a4
github.com/spf13/cobra.(*Command).ExecuteC(0x2ac6c80, 0x0, 0x0, 0xc00059a201)
        C:/Users/shari/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:950 +0x350
github.com/spf13/cobra.(*Command).Execute(...)
        C:/Users/shari/go/pkg/mod/github.com/spf13/cobra@v1.0.0/command.go:887
k8s.io/minikube/cmd/minikube/cmd.Execute()
        C:/Users/shari/Documents/minikube/cmd/minikube/cmd/root.go:112 +0x6ba
main.main()
        C:/Users/shari/Documents/minikube/cmd/minikube/main.go:66 +0xed

After

* minikube v1.10.0 on Microsoft Windows 10 Pro 10.0.18363 Build 18363
* Automatically selected the hyperv driver. Other choices: docker, virtualbox
* Starting control plane node minikube in cluster minikube
* Creating hyperv VM (CPUs=2, Memory=6000MB, Disk=20000MB) ...
* Preparing Kubernetes v1.18.1 on Docker 19.03.8 ...
* Verifying Kubernetes components...
* Enabled addons: default-storageclass, storage-provisioner
* Done! kubectl is now configured to use "minikube"

closes #8080

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: sharifelgamal

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• OWNERS [sharifelgamal]

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[codecov-io]

Codecov Report

Merging #8103 into master will decrease coverage by 0.02%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #8103      +/-   ##
==========================================
- Coverage   35.37%   35.35%   -0.03%     
==========================================
  Files         146      146              
  Lines        9315     9321       +6     
==========================================
  Hits         3295     3295              
- Misses       5621     5627       +6     
  Partials      399      399              

Impacted Files	Coverage Δ
pkg/minikube/cluster/ip.go	0.00% <0.00%> (ø)

[medyagh]

/ok-to-test