[NET]: Change 1500 to ETH_DATA_LEN in some files

These patches add the header linux/if_ether.h and change 1500 to
ETH_DATA_LEN in some files.

Signed-off-by: Kris Katterjohn <kjak@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 46f9d9c..912c42f 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -28,6 +28,7 @@
 #include <linux/inetdevice.h>
 #include <linux/igmp.h>
 #include <linux/netfilter_ipv4.h>
+#include <linux/if_ether.h>
 
 #include <net/sock.h>
 #include <net/ip.h>
@@ -1140,7 +1141,7 @@
 
 	dev->type		= ARPHRD_IPGRE;
 	dev->hard_header_len 	= LL_MAX_HEADER + sizeof(struct iphdr) + 4;
-	dev->mtu		= 1500 - sizeof(struct iphdr) - 4;
+	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 4;
 	dev->flags		= IFF_NOARP;
 	dev->iflink		= 0;
 	dev->addr_len		= 4;
@@ -1152,7 +1153,7 @@
 	struct ip_tunnel *tunnel;
 	struct iphdr *iph;
 	int hlen = LL_MAX_HEADER;
-	int mtu = 1500;
+	int mtu = ETH_DATA_LEN;
 	int addend = sizeof(struct iphdr) + 4;
 
 	tunnel = (struct ip_tunnel*)dev->priv;