bsc: properly f_rslem_unregister() released channels

After the RSL RF Release has happened, by definition the RSL_Emulation
should no longer direct RSL messages on that chan_nr to the test
component that used to own the chan_nr in the ConnectionTable.

Before this patch, re-using e.g. an already freed SDCCH would result in
non-obvious test failure. This is most relevant for generic functions
called from various tests, but fixing all occurences anyway.

Related: SYS#5130
Change-Id: I764ea2ed9af9358adeb42d7ed46b84f30f1e224c
1 file changed