handover_test: vty echo

Echo each handover_test command on the test output, to help with
understanding the exact point of a test failure.

Even nicer would be a general echo of all VTY commands, but the VTY
currently does not support that feature. Refraining from a libosmocore
patch just for these test scripts...

Change-Id: Ifc307a7d0b7e3caa355f8cee88778762b529ad71
1 file changed