bsc: TC_assignment_csd: delete mgcp EP after clear

Fix the test for sccplite, where it fails at the third rate with:
  Crit already present{ connid := omit, endpoint := omit, transid := omit }

For each rate that gets tested, a new expectation (Crit) gets set by
f_tc_assignment_csd() (f_establish_fully() -> f_create_mgcp_expect()).

If the expectation already exists at this point, it leads to the error
above. While the rate gets tested, the expectation gets removed in
MGCP_Emulation:main() (ops.create_cb.apply -> ExpectedCreateCallback()),
but only if the EP is not known.

So without this patch:
* T_14k4: passes, EP is not known, Crit gets removed
* T_9k6: passes, EP is known, Crit does not get removed
* T_4k8: error, because Crit already exists

Related: OS#4393
Change-Id: Ib8d27a670931105f45b994799c4757fffabdf97d
1 file changed