Revert "use /data for filer"

This reverts commit 469afddc80.

docker/entrypoint.sh

@@ -29,6 +29,7 @@ case "$1" in
   	;;
 
   'filer')
+  	exec mkdir /data/filerdb
   	ARGS="-ip `hostname -i` "
   	if [ -n "$MASTER_PORT_9333_TCP_ADDR" ] ; then
 		ARGS="$ARGS -master=$MASTER_PORT_9333_TCP_ADDR:$MASTER_PORT_9333_TCP_PORT"

docker/filer.toml

@@ -1,3 +1,3 @@
 [leveldb]
 enabled = true
-dir = "/data"
+dir = "/data/filerdb"