BTS_Tests_SMSCB: ensure f_shutdown() is called in all test cases

This fixes sporadic test case failures due to race conditions.

Change-Id: I3f2c327e1e44d5decd4a936f063af649687f950a

bts/BTS_Tests_SMSCB.ttcn

@@ -1005,6 +1005,8 @@ testcase TC_etws_p1ro() runs on test_CT {
 			setverdict(fail, "Segment ", i, " not received often enough");
 		}
 	}
+
+	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 }
 
 /* Ensure only Paging Type 1 without ETWS Primary Notification are sent after disabling them */
@@ -1045,6 +1047,8 @@ testcase TC_etws_p1ro_end() runs on test_CT {
 		setverdict(pass);
 		}
 	}
+
+	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 }
 
 /* Ensure ETWS Primary Notification is passed from RSL to PCU interface */
@@ -1070,6 +1074,8 @@ testcase TC_etws_pcu() runs on test_CT {
 		setverdict(fail, "PCU socket timeout receiving APP INFO (ETWS)");
 		}
 	}
+
+	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 }