hodec2: code dup / cosmetics

In handover_decision_2.c, instead of repeating a similar loop four
times, put that loop in a function and parameterize it.

Prepare for a fix of two problems in handover decision 2, see
I2704899c85c35dfd4eba43468452483f40016ca2.

Change-Id: I7c32d08e490a88a7f044b0a71dc4b07d748dd572
1 file changed