vty: 'handover any': pick more random chans, use lchan_select_by_type()

The 'handover any' VTY command is only useful for testing. It is even more
useful if it doesn't always pick the first used lchan but produces more random
handovers.

The algorithm takes a random number as input, iterates over used lchans once,
and if the random number is larger, takes modulo of the nr of used lchans
counted. A second iteration will then produce a match.

Instead of figuring out the lchan type logic in bsc_vty.c, just use
lchan_select_by_type();

Change-Id: I50b70e02d665b967e401db65581e110bc83101e7
1 file changed