set mtu for DinD (#314)

Author: horis233

prow/docker/build-tool/docker-entrypoint.sh

@@ -21,14 +21,9 @@ if [ ! -f /etc/docker/daemon.json ]; then
   mkdir -p /etc/docker
   touch /etc/docker/daemon.json
   echo "Enable experimental mode for docker "
-  ARCH=$(uname -m)
   # fix the MTU settings for DinD daemon
-  if [ ${ARCH} == "ppc64le" ] ; then
-    docker_mtu=8940
-    jq -n --arg mtu ${docker_mtu} --arg enable true '{"mtu":$mtu|tonumber,"experimental":$enable| test("true")}' > /etc/docker/daemon.json
-  else
-    jq -n --arg enable true '{"experimental":$enable| test("true")}' > /etc/docker/daemon.json
-  fi
+  docker_mtu=8940
+  jq -n --arg mtu ${docker_mtu} --arg enable true '{"mtu":$mtu|tonumber,"experimental":$enable| test("true")}' > /etc/docker/daemon.json
 fi
 
 # Start docker daemon and wait for dockerd to start