Convert to use rta_getattr_ functions

User new functions (inspired by libmnl) to do type safe access
of routeing attributes
diff --git a/ip/ipneigh.c b/ip/ipneigh.c
index 313cc63..93cfba2 100644
--- a/ip/ipneigh.c
+++ b/ip/ipneigh.c
@@ -282,7 +282,7 @@
 	}
 
 	if (tb[NDA_PROBES] && show_stats) {
-		__u32 p = *(__u32 *) RTA_DATA(tb[NDA_PROBES]);
+		__u32 p = rta_getattr_u32(tb[NDA_PROBES]);
 		fprintf(fp, " probes %u", p);
 	}