ipv4: generalize gre_handle_offloads

This patch makes gre_handle_offloads() more generic
and rename it to iptunnel_handle_offloads()

This will be used to add GSO/TSO support to IPIP tunnels.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/gre.h b/include/net/gre.h
index 57e4afd..dcd9ae3 100644
--- a/include/net/gre.h
+++ b/include/net/gre.h
@@ -38,7 +38,13 @@
 
 void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
 		      int hdr_len);
-struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum);
+
+static inline struct sk_buff *gre_handle_offloads(struct sk_buff *skb,
+						  bool gre_csum)
+{
+	return iptunnel_handle_offloads(skb, gre_csum, SKB_GSO_GRE);
+}
+
 
 static inline int ip_gre_calc_hlen(__be16 o_flags)
 {