BTS_Tests: properly release DCCH in f_TC_acch_overpower()

Currently the TC_acch_overpower_* testcases are all passing without
any sporadic failures.  However, most of them start failing due to
a DTE (some RSLEM related race condition) if I apply a patch [1] to
trxcon removing its internal TDMA clock module.

I don't know why this happens, but releasing the DCCH after executing
all testcase steps in f_TC_acch_overpower() makes that DTE go away.

Change-Id: I658e78ad8d4dc86403d22b5380ddd9a140f8c71c
Related: [1] osmocom-bb.git Ic8a5b6277c6b16392026e0557376257d71c9d230
Related: OS#5500
1 file changed