sccp_sap_up(): Fix never-hit "default" case in switch

As the default was called "defualt", it became a standard C label
and was never actually performing any default catch-all behavior.

As we didn't use -Wall, gcc never warned us about it so far :/

Change-Id: I9dbad21e75a55ad91b12d3d3ee8bd6dfb5326c3e
diff --git a/src/hnbgw_cn.c b/src/hnbgw_cn.c
index 81ef670..3238f00 100644
--- a/src/hnbgw_cn.c
+++ b/src/hnbgw_cn.c
@@ -389,7 +389,7 @@
 	case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION):
 		rc = handle_cn_disc_ind(cnlink, &prim->u.disconnect, oph);
 		break;
-	defualt:
+	default:
 		LOGP(DMAIN, LOGL_ERROR,
 			"Received unknown prim %u from SCCP USER SAP\n",
 			OSMO_PRIM_HDR(oph));