jffs2reset produces no output when run by ssh directly

Normal operation:
```sh
$ ssh root@openwrt

root@OpenWrt:~# jffs2reset 
This will erase all settings and remove any installed packages. Are you sure? [N/y]
N
root@OpenWrt:~#
```

When run with `ssh` directly, no output produced:
```sh
$ ssh root@openwrt jffs2reset
# waiting for input here
N
$ 
```
