vxlan: remove the useless header file protocol.h

This header file is not used in vxlan.c file.
Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

@@ -27,7 +27,6 @@
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 #include <net/vxlan.h>
-#include <net/protocol.h>
 
 #if IS_ENABLED(CONFIG_IPV6)
 #include <net/ip6_tunnel.h>