libmsc/sgs_iface.c: fix copy-paste error

Change-Id: I57b773659302ad4c92b6e670c6156e90a50189ba
diff --git a/src/libmsc/sgs_iface.c b/src/libmsc/sgs_iface.c
index 4f262a5..f2e74cb 100644
--- a/src/libmsc/sgs_iface.c
+++ b/src/libmsc/sgs_iface.c
@@ -51,7 +51,7 @@
 
 /* A pointer to the GSM network we work with. By the current paradigm,
  * there can only be one gsm_network per MSC. The pointer is set once
- * when calling a_init() */
+ * when calling sgs_iface_init() */
 static struct gsm_network *gsm_network = NULL;
 
 static struct osmo_fsm sgs_vlr_reset_fsm;