hlr.c: replace deprecated osmo_gsup_get_err_msg_type()

Use OSMO_GSUP_TO_MSGT_ERROR() instead. The other function has been
deprecated in [1].

Remove the < 0 return check, because the macro doesn't do any error
handling. It relies on all "request" messages having an appropriate
"error" message, which is part of the GSUP spec now (see [2]).

[1] change-id I46d9f2327791978710e2f90b4d28a3761d723d8f (libosmocore)
[2] change-id Iec1b4ce4b7d8eb157406f006e1c4241e8fba2cd6 (osmo-gsm-manuals)

Change-Id: I5435ec4c29d6acee814c33499c68d18aaa91d4fb
diff --git a/src/hlr.c b/src/hlr.c
index 0098a32..7046180 100644
--- a/src/hlr.c
+++ b/src/hlr.c
@@ -379,16 +379,10 @@
 static int gsup_send_err_reply(struct osmo_gsup_conn *conn, const char *imsi,
 				enum osmo_gsup_message_type type_in, uint8_t err_cause)
 {
-	int type_err = osmo_gsup_get_err_msg_type(type_in);
+	int type_err = OSMO_GSUP_TO_MSGT_ERROR(type_in);
 	struct osmo_gsup_message gsup_reply = {0};
 	struct msgb *msg_out;
 
-	if (type_err < 0) {
-		LOGP(DMAIN, LOGL_ERROR, "unable to determine error response for %s\n",
-			osmo_gsup_message_type_name(type_in));
-		return type_err;
-	}
-
 	OSMO_STRLCPY_ARRAY(gsup_reply.imsi, imsi);
 	gsup_reply.message_type = type_err;
 	gsup_reply.cause = err_cause;