PCU_Tests_RAW.ttcn: fix the expectations of TC_cs_lqual_ul_tbf

As it turned out, OsmoPCU is not supposed to change the Coding
Scheme immediately when the recent link quality value leaves the
current window. Instead, in order to avoid rapid changes of the
Coding Scheme, it also takes the previous value into account.
Thus the current Coding Scheme is only changed if both current
and old values fit into a new window.

This change makes the test case pass.

Change-Id: I5d503d5a9c46cb9de84fbabd2d591afbe4216fdb
1 file changed