gsm0408: Provide unique strings for the gsm 04.08 message

At Rhizomatica we see that some GSM 04.08 messages are leaked and
have no other indication if that is Call Control, SMS or something
else.
diff --git a/openbsc/src/libmsc/gsm_04_80.c b/openbsc/src/libmsc/gsm_04_80.c
index b30f9ee..f1d75f2 100644
--- a/openbsc/src/libmsc/gsm_04_80.c
+++ b/openbsc/src/libmsc/gsm_04_80.c
@@ -65,7 +65,7 @@
 			       const struct msgb *in_msg, const char *response_text,
 			       const struct ussd_request *req)
 {
-	struct msgb *msg = gsm48_msgb_alloc();
+	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 USSD RSP");
 	struct gsm48_hdr *gh;
 	uint8_t *ptr8;
 	int response_len;
@@ -113,7 +113,7 @@
 			     const struct msgb *in_msg,
 			     const struct ussd_request *req)
 {
-	struct msgb *msg = gsm48_msgb_alloc();
+	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 USSD REJ");
 	struct gsm48_hdr *gh;
 
 	/* First insert the problem code */
@@ -163,7 +163,7 @@
 	struct gsm48_hdr *gh;
 	struct msgb *msg;
 
-	msg = gsm48_msgb_alloc();
+	msg = gsm48_msgb_alloc_name("GSM 04.08 USSD REL COMPL");
 	if (!msg)
 		return -1;