ns2: Memory allocation failures are ENOMEM, not ENOSPC

ENOSPC is used with non-volatile (disk) storage, while ENOMEM is
customarily used for RAM allocation failures.

Change-Id: Ia4c16d8278dc30c7cc69169b18428cda5272738d
diff --git a/src/gb/gprs_ns2_fr.c b/src/gb/gprs_ns2_fr.c
index 953f4ca..c32bce8 100644
--- a/src/gb/gprs_ns2_fr.c
+++ b/src/gb/gprs_ns2_fr.c
@@ -738,7 +738,7 @@
 	bind->dump_vty = dump_vty;
 	priv = bind->priv = talloc_zero(bind, struct priv_bind);
 	if (!priv) {
-		rc = -ENOSPC;
+		rc = -ENOMEM;
 		goto err_bind;
 	}