bsc_test: drop "scan to MSC" code path

The TEST_SCAN_TO_MSC is completely unused, but still the code linked
bsc_scan_bts_msg() for the unused code path. This is unlikely to ever be
expanded. Remove TEST_SCAN_TO_MSC and reduce linking requirements.

(I am this close to dropping the test entirely to avoid continuous linking
annoyance, but ok, since nothing else tests timezones AFAIK, keeping it.)

Change-Id: I27521950432e412f919cde811c9473557d0ec25e
diff --git a/tests/bsc/bsc_test.c b/tests/bsc/bsc_test.c
index 106b08b..08d3760 100644
--- a/tests/bsc/bsc_test.c
+++ b/tests/bsc/bsc_test.c
@@ -43,7 +43,6 @@
 
 enum test {
 	TEST_SCAN_TO_BTS,
-	TEST_SCAN_TO_MSC,
 };
 
 /* GSM 04.08 MM INFORMATION test message */
@@ -158,12 +157,6 @@
 			/* override timezone of msg coming from the MSC */
 			result = bsc_scan_msc_msg(conn, msg);
 			break;
-		case TEST_SCAN_TO_MSC:
-			/* override timezone of msg coming from the BSC */
-			/* FIXME: no test for this case is defined in
-			 * test_scan_defs[], so this is never used. */
-			result = bsc_scan_bts_msg(conn, msg);
-			break;
 		default:
 			abort();
 			break;