SGSN: move TLLI unassignment into separate function

Change-Id: Ia4df145ab03ebcaad70a13601cff60c488a5de54
Related: OS#1582
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index 8f9f453..98439de 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -770,7 +770,7 @@
 	/* No MM context found */
 	LOGP(DGPRS, LOGL_INFO, "Deleting orphaned LLME, TLLI 0x%08x\n",
 	     llme->tlli);
-	gprs_llgmm_assign(llme, llme->tlli, 0xffffffff, GPRS_ALGO_GEA0, NULL);
+	gprs_llgmm_unassign(llme);
 }
 
 static void sgsn_llme_check_cb(void *data_)