[LTP] test_net.sh: Require to redefine less variables

[Alexey Kodanev]

On 02/21/2017 02:18 PM, Petr Vorel wrote:
> Hi Alexey,
>
>> Ah, I see, we can run them with network.sh which source test_net.sh, OK.
>> Though, the left users of these functions are stress/tcp/udp/route and
>> multicast stress tests...I'll post updates for the first three soon.
> What exactly are you going to do?
>
> I suppose I should wait with this until you do you push your cleanup.

Update to source test_net.sh and ipsec_lib.sh. It's not necessary to wait,
these tests still can be run as is by exporting old-style variables.

Thanks,
Alexey