rt_names can't be const

Needs to be built at runtime.
diff --git a/lib/rt_names.c b/lib/rt_names.c
index 1698036..e87c65d 100644
--- a/lib/rt_names.c
+++ b/lib/rt_names.c
@@ -196,7 +196,7 @@
 	return 0;
 }
 
-static const char * rtnl_rtscope_tab[256] = {
+static char * rtnl_rtscope_tab[256] = {
 	"global",
 };