[COMMON] Fix condition equality bashisms

pointed out by checkbashisms.

$ mycmd=$(tox -e checkbashisms | grep "(should be 'b = a')" | sed -e
  "s@^[^.]*\(.[^ ]*\) line \([0-9]*\) .*@sed -i -e '\2s/==/=/g' \1;@")

$ eval $mycmd

Issue-ID: OOM-2643
Signed-off-by: Guillaume Lambert <guillaume.lambert@orange.com>
Change-Id: I9032130bc4717e111de11a73187c2f1052376e45
diff --git a/kubernetes/contrib/tools/rke/rke_setup.sh b/kubernetes/contrib/tools/rke/rke_setup.sh
index cde7d4c..7950e0c 100755
--- a/kubernetes/contrib/tools/rke/rke_setup.sh
+++ b/kubernetes/contrib/tools/rke/rke_setup.sh
@@ -258,14 +258,14 @@
   helm init --service-account tiller
   kubectl -n kube-system  rollout status deploy/tiller-deploy
   echo "upgrade server side of helm in kubernetes"
-  if [ "$USERNAME" == "root" ]; then
+  if [ "$USERNAME" = "root" ]; then
     helm version
   else
     sudo helm version
   fi
   echo "sleep 30"
   sleep 30
-  if [ "$USERNAME" == "root" ]; then
+  if [ "$USERNAME" = "root" ]; then
     helm init --upgrade
   else
     sudo helm init --upgrade
@@ -273,13 +273,13 @@
   echo "sleep 30"
   sleep 30
   echo "verify both versions are the same below"
-  if [ "$USERNAME" == "root" ]; then
+  if [ "$USERNAME" = "root" ]; then
     helm version
   else
     sudo helm version
   fi
   echo "start helm server"
-  if [ "$USERNAME" == "root" ]; then
+  if [ "$USERNAME" = "root" ]; then
     helm serve &
   else
     sudo helm serve &
@@ -287,7 +287,7 @@
   echo "sleep 30"
   sleep 30
   echo "add local helm repo"
-  if [ "$USERNAME" == "root" ]; then
+  if [ "$USERNAME" = "root" ]; then
     helm repo add local http://127.0.0.1:8879
     helm repo list
   else