use well defined shell expression test
use well defined shell expression test

https://github.com/koalaman/shellcheck/wiki/SC2166

Change-Id: Ifa6f13ed17a945ec6e906c002860ca5e77488f82

opennetworkinglab/onos,osinstom/onos,oplinkoms/onos,gkatsikas/onos,gkatsikas/onos,kuujo/onos,osinstom/onos,gkatsikas/onos,kuujo/onos,kuujo/onos,oplinkoms/onos,opennetworkinglab/onos,opennetworkinglab/onos,oplinkoms/onos,oplinkoms/onos,oplinkoms/onos,kuujo/onos,kuujo/onos,oplinkoms/onos,gkatsikas/onos,opennetworkinglab/onos,gkatsikas/onos,oplinkoms/onos,opennetworkinglab/onos,gkatsikas/onos,osinstom/onos,osinstom/onos,kuujo/onos,osinstom/onos,opennetworkinglab/onos,kuujo/onos