Reference docker without using the shell PATH

Change-Id: I9e3011190c2e4c008c25fd9bc8c86ddcc591685a
diff --git a/jjb/onos/onos-docker-build.sh b/jjb/onos/onos-docker-build.sh
index 15c1f9d..856abc9 100644
--- a/jjb/onos/onos-docker-build.sh
+++ b/jjb/onos/onos-docker-build.sh
@@ -14,6 +14,9 @@
 onos-buck build onos
 
 # build and deploy the Docker image
-docker build -t onosproject/onos:${ONOS_VERSION} .
-docker login --username ${DOCKERHUB_USERNAME} --password ${DOCKERHUB_PASSWORD}
-docker push onosproject/onos:${ONOS_VERSION}
+# build and deploy the Docker image
+DOCKER="/usr/local/bin/docker"
+$DOCKER build -t onosproject/onos:${ONOS_VERSION} .
+$DOCKER login --username ${DOCKERHUB_USERNAME} --password ${DOCKERHUB_PASSWORD}
+$DOCKER push onosproject/onos:${ONOS_VERSION}
+