BTS: release the channel in TC_ms_pwr_ctrl_{constant,pf_ewma}

Since recently, we do have NOPE indications in the virtual Um
environment.  Somehow this broke test cases for the MS power
control.  Releasing the channel makes everything work again.

Change-Id: I6a204bbecfe116aa302eae28ff24d6bb899fa8b7
Related: SYS#5313, OS#1569, OS#1866
diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 547ada2..a6ccf30 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -7128,6 +7128,10 @@
 				 num_blocks, " were not handled");
 		}
 	}
+
+	/* Release the channel */
+	f_rsl_chan_deact();
+	f_L1CTL_DM_REL_REQ(L1CTL, g_chan_nr);
 }
 testcase TC_ms_pwr_ctrl_constant() runs on test_CT {
 	var ConnHdlr vc_conn;
@@ -7185,6 +7189,10 @@
 				 num_blocks, " were not handled");
 		}
 	}
+
+	/* Release the channel */
+	f_rsl_chan_deact();
+	f_L1CTL_DM_REL_REQ(L1CTL, g_chan_nr);
 }
 testcase TC_ms_pwr_ctrl_pf_ewma() runs on test_CT {
 	var ConnHdlr vc_conn;