gtphub: log: add side str to msg for reused TEI

Sponsored-by: On-Waves ehi
diff --git a/openbsc/src/gprs/gtphub.c b/openbsc/src/gprs/gtphub.c
index e2f3a54..4708f37 100644
--- a/openbsc/src/gprs/gtphub.c
+++ b/openbsc/src/gprs/gtphub.c
@@ -1274,8 +1274,9 @@
 				 * must be stale, then. */
 				LOG(LOGL_NOTICE,
 				    "Expiring tunnel due to reused TEI:"
-				    " peer %s sent %s TEI %x,"
+				    " %s peer %s sent %s TEI %x,"
 				    " previously used by tunnel %s...\n",
+				    gtphub_side_idx_names[side_idx],
 				    gtphub_port_str(te->peer),
 				    gtphub_plane_idx_names[plane_idx],
 				    te->tei_orig,