Compiler warnings fixes round 1.
diff --git a/ospfd/ospf_route.c b/ospfd/ospf_route.c
index 9280767..15331fd 100644
--- a/ospfd/ospf_route.c
+++ b/ospfd/ospf_route.c
@@ -640,7 +640,7 @@
     zlog_info("ospf_intra_add_stub(): Stop");
 }
 
-char *ospf_path_type_str[] =
+const char *ospf_path_type_str[] =
 {
   "unknown-type",
   "intra-area",