Uneeded +1 with result print on latency_test()

[jwbensley]

Email from Bruno:

In the file tests.cpp, function latency_test(), the final printf() in Tx mode prints :

`QM_TEST->TIMEOUT_COUNT += 1,`

as the timed out frames count. I think this is an error.

In reference to this line:

https://github.com/jwbensley/Etherate/blob/master/tests.cpp#L854

[jwbensley]

Fixed in beta 0.13.