gprs_ns2: Log all transmitted SNS messages

We already have similar log statements for all NS-{RESET,BLOCK,UNBLOCK,...}
and it's confusing that even a debug-level NS log file doesn't show
transmitting SNS messages at all.

Change-Id: I0d31c3911d3acd6ac7296c370e920d53412d8289
diff --git a/src/gb/gprs_ns2_message.c b/src/gb/gprs_ns2_message.c
index ddf7285..535d5be 100644
--- a/src/gb/gprs_ns2_message.c
+++ b/src/gb/gprs_ns2_message.c
@@ -515,6 +515,9 @@
 		return -EIO;
 	}
 
+	LOGNSVC(nsvc, LOGL_INFO, "Tx SNS-ACK (trans_id=%u, cause=%s, num_ip4=%u, num_ip6=%u)\n",
+		trans_id, cause ? gprs_ns2_cause_str(*cause) : "NULL", num_ip4_elems, num_ip6_elems);
+
 	nsei = osmo_htons(nsvc->nse->nsei);
 
 	msg->l2h = msgb_put(msg, sizeof(*nsh));
@@ -573,6 +576,9 @@
 		return -EIO;
 	}
 
+	LOGNSVC(nsvc, LOGL_INFO, "Tx SNS-CONFIG (end_flag=%u, num_ip4=%u, num_ip6=%u)\n",
+		end_flag, num_ip4_elems, num_ip6_elems);
+
 	nsei = osmo_htons(nsvc->nse->nsei);
 
 	msg->l2h = msgb_put(msg, sizeof(*nsh));
@@ -621,6 +627,9 @@
 		return -EIO;
 	}
 
+	LOGNSVC(nsvc, LOGL_INFO, "Tx SNS-CONFIG-ACK (cause=%s)\n",
+		cause ? gprs_ns2_cause_str(*cause) : "NULL");
+
 	nsei = osmo_htons(nsvc->nse->nsei);
 
 	msg->l2h = msgb_put(msg, sizeof(*nsh));
@@ -666,6 +675,9 @@
 		return -EIO;
 	}
 
+	LOGNSVC(nsvc, LOGL_INFO, "Tx SNS-SIZE (reset=%u, max_nr_nsvc=%u, num_ip4=%u, num_ip6=%u)\n",
+		reset_flag, max_nr_nsvc, ip4_ep_nr, ip6_ep_nr);
+
 	nsei = osmo_htons(nsvc->nse->nsei);
 
 	msg->l2h = msgb_put(msg, sizeof(*nsh));
@@ -705,6 +717,9 @@
 		return -EIO;
 	}
 
+	LOGNSVC(nsvc, LOGL_INFO, "Tx SNS-SIZE-ACK (cause=%s)\n",
+		cause ? gprs_ns2_cause_str(*cause) : "NULL");
+
 	nsei = osmo_htons(nsvc->nse->nsei);
 
 	msg->l2h = msgb_put(msg, sizeof(*nsh));