net: move *skb_get_poff declarations into correct header

Since these functions are defined in flow_dissector.c, move header
declarations from skbuff.h into flow_dissector.h

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 9045e2a..9332a0a 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -58,6 +58,7 @@
 #include <net/ipv6.h>
 #include <net/ip.h>
 #include <net/dsa.h>
+#include <net/flow_dissector.h>
 #include <linux/uaccess.h>
 
 __setup("ether=", netdev_boot_setup);