handover_test: saner ho request handling

Similar to chan act handling, clarify and safeguard HO Request handling.
Ensure that each HO Request is handled by the test script.

Place unhandled HO Requests in new_ho_req pointer, moving to last_ho_req
upon handling it. Instead of the got_ho_req flag and additional
ho_req_lchan pointer, just keep a last_ho_req pointer.

Drop a bunch of utterly useless RSL message parsing code.

Fix unhandled HO Request in test_max_handovers.ho_vty.

Change-Id: I0a664f24d7dd3d7b254b29675fdc49cd70a1a480
2 files changed