During "Port forwarding" e2e tests, the following panic happened:
```
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x64981d]
goroutine 52788 [running]:
panic(0x1830ee0, 0xc4200100c0)
/usr/lib/golang/src/runtime/panic.go:500 +0x1a1
github.com/kubernetes-incubator/cri-o/oci.(*Runtime).UpdateStatus(0xc4202afc00,
0x0, 0x0, 0x0)
/home/amurdaca/go/src/github.com/kubernetes-incubator/cri-o/oci/oci.go:549
+0x7d
github.com/kubernetes-incubator/cri-o/server.streamService.PortForward(0xc42026e000,
0x0, 0x0, 0x0, 0x0, 0xc420d9af40, 0x40, 0xc400000050, 0x7fe660659a28,
0xc4201cd0e0, ...)
```
The issue is `streamService.PortForward` assumed the first argument to
be the sandbox's infra container ID, thus trying to get it from memory
store using `.state.containers.Get`. Since that ID is of the sandbox
itself, it fails to get the container object from memory and panics in
`UpdateStatus`.
Fix it by looking for the sandbox's infra container ID starting from a
sandbox ID.
Signed-off-by: Antonio Murdaca <runcom@redhat.com>
1e9ef65345