Description of problem:
Before the network started, there is script to check that if the cniserver.sock exists.
https://github.com/openshift/openshift-ansible/blob/master/roles/openshift_sdn/files/sdn.yaml#L51

And it will result that the first line of the sdn log shows the socat error which is confusing:

# oc logs sdn-57gqf -n openshift-sdn | head -10
2018/05/23 02:11:24 socat[9132] E connect(5, AF=1 "/var/run/openshift-sdn/cni-server.sock", 40): No such file or directory
warning: Cannot find existing node-config.yaml, waiting 15s ...
User "sa" set.
Context "default-context" modified.
I0523 02:11:39.977795    9116 start_node.go:304] Reading node configuration from /etc/origin/node/node-config.yaml
I0523 02:11:39.979931    9116 feature_gate.go:190] feature gates: map[RotateKubeletClientCertificate:true RotateKubeletServerCertificate:true]
I0523 02:11:39.980085    9116 start_node.go:454] Starting node networking ip-172-18-13-135.ec2.internal (v3.10.0-0.50.0)
W0523 02:11:39.980320    9116 server.go:195] WARNING: all flags other than --config, --write-config-to, and --cleanup are deprecated. Please begin using a config file ASAP.
I0523 02:11:39.980372    9116 feature_gate.go:226] feature gates: &{{} map[RotateKubeletClientCertificate:true RotateKubeletServerCertificate:true]}
I0523 02:11:39.981622    9116 transport.go:160] Refreshing client certificate from store



Version-Release number of selected component (if applicable):
v3.10.0-0.50.0
ose-node:v3.10               58027d498eba

How reproducible:
always

Steps to Reproduce:
1. Setup ocp cluster
2. Check the first lines of the sdn pod log
3.

Actual results:
It prints the confusing socat error to the sdn log.

Expected results:
Should redirect the stderr to /dev/null to avoid confusing.

Additional info: