hs-test: return error if connecting to vpp fails

Type: fix

Fix case where no error code would be returned if vpp was launched,
but then exited due to invalid configuration.

Change-Id: I54d526629a2ee0206227615ffb6cb658779f93a0
Signed-off-by: Hadi Rayan Al-Sandid <halsandi@cisco.com>

extras/hs-test/infra/vppinstance.go

@@ -184,6 +184,7 @@ func (vpp *VppInstance) Start() error {
 	e := <-connEv
 	if e.State != core.Connected {
 		vpp.getSuite().Log("connecting to VPP failed: " + fmt.Sprint(e.Error))
+		return e.Error
 	}
 
 	ch, err := conn.NewStream(