fix array index out of bounds

[novahe]

panic stack:

panic: runtime error: index out of range [-1]

goroutine 565 [running]:
k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary.Uint64Slice.GetPercentile({0xc001216ba0?, 0x1, 0x1000000000008?}, 0x3fee666666666666)
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary/percentiles.go:50 +0x16a
k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary.(*resource).GetAllPercentiles(0xc001026440)
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary/percentiles.go:123 +0xef
k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary.GetDerivedPercentiles({0xc000435848, 0x1, 0xc0010265a0?})
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary/percentiles.go:145 +0x2a8
k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary.(*StatsSummary).getDerivedUsage(0x7fac0c1608c0?, 0x3c)
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary/summary.go:157 +0x252
k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary.(*StatsSummary).updateDerivedStats(0xc001f0b040)
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary/summary.go:127 +0x1c9
k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary.(*StatsSummary).AddSample(_, {{0xc1e67c2f39724857, 0xeeb2856cf, 0x55d669537980}, {{0xcef01a09f, {0x0, 0x0, 0x0}, 0xa33478c80, 0x260903c80}, ...}, ...})
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/summary/summary.go:88 +0x3bb
k8s.io/kubernetes/vendor/github.com/google/cadvisor/manager.(*containerData).updateStats(0xc001c37b80)
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/manager/container.go:677 +0x345
k8s.io/kubernetes/vendor/github.com/google/cadvisor/manager.(*containerData).housekeepingTick(0xc001c37b80, 0x7c?, 0x5f5e100)
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/manager/container.go:595 +0x165
k8s.io/kubernetes/vendor/github.com/google/cadvisor/manager.(*containerData).housekeeping(0xc001c37b80)
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/manager/container.go:543 +0x446
created by k8s.io/kubernetes/vendor/github.com/google/cadvisor/manager.(*containerData).Start
	/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/google/cadvisor/manager/container.go:130 +0x56

[google-cla]

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[novahe]

@Creatone @bobbypage @haircommander review will be appreciated.

[novahe]

PTAL @SuperQ @cwangVT

[SuperQ]

Minor nit, otherwise LGTM.

[novahe]

Use testtable to make it clearer, please take a look again.

[novahe]

PTAL @iwankgb
/ok-to-test