net: shell: Do not access NULL pointer if interface is down

Normally network interface is always UP, but Bluetooth
interfaces are down until connected. So if this is the case,
then check the interface status before trying to access variables
that are NULL. This was seen with "net iface" shell command when
BT was enabled.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
2 files changed