fix gsm0408_test: properly free bts struct after each test

Add missing deletion of osmo_stat_item_group_free(bts->bts_statg).
Add missing bts free after test_si_ba_ind().

Log deallocation, update expected test output.

This fixes some of the errors of gsm0408_test's SI tests, as revealed by a
sanitizer build using gcc (Debian 7.3.0-12) 7.3.0.

Fixes:

=================================================================
==19273==ERROR: AddressSanitizer: heap-use-after-free on address 0x60d0000004b8 at pc 0x7f1561a94621 bp 0x7ffe7a7a64a0 sp 0x7ffe7a7a6498
WRITE of size 8 at 0x60d0000004b8 thread T0
    #0 0x7f1561a94620 in __llist_add ../../../src/libosmocore/include/osmocom/core/linuxlist.h:75
    #1 0x7f1561a94620 in llist_add ../../../src/libosmocore/include/osmocom/core/linuxlist.h:90
    #2 0x7f1561a94620 in osmo_stat_item_group_alloc ../../../src/libosmocore/src/stat_item.c:141
    #3 0x5574f6a19935 in gsm_bts_alloc ../../../../src/osmo-bsc/src/libbsc/gsm_data.c:728
    #4 0x5574f6a12920 in bts_init ../../../../src/osmo-bsc/tests/gsm0408/gsm0408_test.c:123
    #5 0x5574f6a0ddb3 in test_si2q_e ../../../../src/osmo-bsc/tests/gsm0408/gsm0408_test.c:192
    #6 0x5574f6a0ddb3 in main ../../../../src/osmo-bsc/tests/gsm0408/gsm0408_test.c:824
    #7 0x7f156061aa86 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21a86)
    #8 0x5574f6a10339 in _start (/n/s/dev/make/osmo-bsc/tests/gsm0408/gsm0408_test+0xfc339)

Change-Id: I1ebbd8cc0622ce1a061e933813829b1f770072dc
diff --git a/tests/gsm0408/gsm0408_test.c b/tests/gsm0408/gsm0408_test.c
index 0a2adcd..9fd4ac7 100644
--- a/tests/gsm0408/gsm0408_test.c
+++ b/tests/gsm0408/gsm0408_test.c
@@ -132,6 +132,16 @@
 	return bts;
 }
 
+#define bts_del(bts) _bts_del(bts, __func__)
+static inline void _bts_del(struct gsm_bts *bts, const char *msg)
+{
+	osmo_stat_item_group_free(bts->bts_statg);
+	rate_ctr_group_free(bts->bts_ctrs);
+	/* no need to llist_del(&bts->list), we never registered the bts there. */
+	talloc_free(bts);
+	printf("BTS deallocated OK in %s()\n", msg);
+}
+
 static inline void test_si2q_segfault(struct gsm_network *net)
 {
 	struct gsm_bts *bts = bts_init(tall_bsc_ctx, net, __func__);
@@ -141,8 +151,7 @@
 	_bts_uarfcn_add(bts, 10612, 319, 0);
 	gen(bts, __func__);
 
-	rate_ctr_group_free(bts->bts_ctrs);
-	talloc_free(bts);
+	bts_del(bts);
 }
 
 static inline void test_si2q_mu(struct gsm_network *net)
@@ -158,8 +167,7 @@
 	_bts_uarfcn_add(bts, 10613, 164, 0);
 	_bts_uarfcn_add(bts, 10613, 14, 0);
 
-	rate_ctr_group_free(bts->bts_ctrs);
-	talloc_free(bts);
+	bts_del(bts);
 }
 
 static inline void test_si2q_u(struct gsm_network *net)
@@ -183,8 +191,7 @@
 	_bts_uarfcn_add(bts, 1982, 14, 0);
 	_bts_uarfcn_add(bts, 1982, 88, 0);
 
-	rate_ctr_group_free(bts->bts_ctrs);
-	talloc_free(bts);
+	bts_del(bts);
 }
 
 static inline void test_si2q_e(struct gsm_network *net)
@@ -213,8 +220,7 @@
 	add_earfcn_b(bts, 1967, 4);
 	add_earfcn_b(bts, 1982, 3);
 
-	rate_ctr_group_free(bts->bts_ctrs);
-	talloc_free(bts);
+	bts_del(bts);
 }
 
 static inline void test_si2q_long(struct gsm_network *net)
@@ -258,8 +264,7 @@
 	_bts_uarfcn_add(bts, 1976, 225, 1);
 	_bts_uarfcn_add(bts, 1976, 226, 1);
 
-	rate_ctr_group_free(bts->bts_ctrs);
-	talloc_free(bts);
+	bts_del(bts);
 }
 
 static void test_mi_functionality(void)
@@ -680,6 +685,8 @@
 	printf("SI5ter: %s\n", osmo_hexdump((uint8_t *)si5ter, rc));
 	/* Validate BA-IND == 1 */
 	OSMO_ASSERT(si5ter->bcch_frequency_list[0] & 0x10);
+
+	bts_del(bts);
 }
 
 struct test_gsm48_ra_id_by_bts {