mgcp_test: fix false negatives in test output

If one test fails, do not print failure for all following tests as well.

Change-Id: I196880b4b34a672ef45042c25f89bc1684363567
diff --git a/tests/mgcp/mgcp_test.c b/tests/mgcp/mgcp_test.c
index 621ee77..c76bd9d 100644
--- a/tests/mgcp/mgcp_test.c
+++ b/tests/mgcp/mgcp_test.c
@@ -2137,7 +2137,7 @@
 static void test_mgcp_codec_decide(void)
 {
 	int i;
-	bool ok = true;
+	bool ok_all = true;
 	printf("\nTesting mgcp_codec_find_convertible()\n");
 
 	for (i = 0; i < ARRAY_SIZE(test_mgcp_codec_find_convertible_cases); i++) {
@@ -2146,6 +2146,7 @@
 		int rc;
 		int conn_i;
 		int c;
+		bool ok = true;
 
 		printf("#%d: %s\n", i, t->descr);
 
@@ -2186,9 +2187,12 @@
 			printf(" ===> SUCCESS: codec decision as expected!\n");
 		else
 			printf(" ===> FAIL: unexpected codec decision!\n");
+
+		if (!ok)
+			ok_all = false;
 	}
 
-	OSMO_ASSERT(ok);
+	OSMO_ASSERT(ok_all);
 }
 
 void test_conn_id_matching(void)