mgcp_test: Add wrong messages as input and check what happens

Test parsing some invalid messages and see if we start to crash.
diff --git a/openbsc/tests/mgcp/mgcp_test.ok b/openbsc/tests/mgcp/mgcp_test.ok
index 1a01c28..092c969 100644
--- a/openbsc/tests/mgcp/mgcp_test.ok
+++ b/openbsc/tests/mgcp/mgcp_test.ok
@@ -1,2 +1,12 @@
-Testing AUEP
+Testing AUEP1
+Testing AUEP2
+Testing CRCX
+Testing CRCX_ZYN
+CRCX_ZYN failed '400 2 FAIL

+'
+Testing EMPTY
+Testing SHORT1
+Testing SHORT2
+Testing SHORT3
+Testing SHORT4
 Done