net: Abstract RTAX_HOPLIMIT metric accesses behind helper.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dst.h b/include/net/dst.h
index 85dee3a..9208b50 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -104,11 +104,24 @@
 #ifdef __KERNEL__
 
 static inline u32
-dst_metric(const struct dst_entry *dst, int metric)
+dst_metric_raw(const struct dst_entry *dst, const int metric)
 {
 	return dst->_metrics[metric-1];
 }
 
+static inline u32
+dst_metric(const struct dst_entry *dst, const int metric)
+{
+	WARN_ON_ONCE(metric == RTAX_HOPLIMIT);
+	return dst_metric_raw(dst, metric);
+}
+
+static inline u32
+dst_metric_hoplimit(const struct dst_entry *dst)
+{
+	return dst_metric_raw(dst, RTAX_HOPLIMIT);
+}
+
 static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
 {
 	dst->_metrics[metric-1] = val;