openvswitch: fix a compilation error when CONFIG_INET is not setW!

Fix a openvswitch compilation error when CONFIG_INET is not set:

=====================================================
   In file included from include/net/geneve.h:4:0,
                       from net/openvswitch/flow_netlink.c:45:
		          include/net/udp_tunnel.h: In function 'udp_tunnel_handle_offloads':
			  >> include/net/udp_tunnel.h:100:2: error: implicit declaration of function 'iptunnel_handle_offloads' [-Werror=implicit-function-declaration]
			  >>      return iptunnel_handle_offloads(skb, udp_csum, type);
			  >>           ^
			  >>           >> include/net/udp_tunnel.h:100:2: warning: return makes pointer from integer without a cast
			  >>           >>    cc1: some warnings being treated as errors

=====================================================

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index c203544..e682b48 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -309,6 +309,7 @@
 
 config NET_UDP_TUNNEL
 	tristate
+	select NET_IP_TUNNEL
 	default n
 
 config NET_FOU
@@ -321,6 +322,20 @@
 	  network mechanisms and optimizations for UDP (such as ECMP
 	  and RSS) can be leveraged to provide better service.
 
+config GENEVE
+	tristate "Generic Network Virtualization Encapsulation (Geneve)"
+	depends on INET
+	select NET_UDP_TUNNEL
+	---help---
+	This allows one to create Geneve virtual interfaces that provide
+	Layer 2 Networks over Layer 3 Networks. Geneve is often used
+	to tunnel virtual network infrastructure in virtualized environments.
+	For more information see:
+	  http://tools.ietf.org/html/draft-gross-geneve-01
+
+	  To compile this driver as a module, choose M here: the module
+
+
 config INET_AH
 	tristate "IP: AH transformation"
 	select XFRM_ALGO
@@ -453,20 +468,6 @@
 	increase provides TCP friendliness.
 	See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
 
-config GENEVE
-	tristate "Generic Network Virtualization Encapsulation (Geneve)"
-	depends on INET
-	select NET_IP_TUNNEL
-	select NET_UDP_TUNNEL
-	---help---
-	This allows one to create Geneve virtual interfaces that provide
-	Layer 2 Networks over Layer 3 Networks. Geneve is often used
-	to tunnel virtual network infrastructure in virtualized environments.
-	For more information see:
-	  http://tools.ietf.org/html/draft-gross-geneve-01
-
-	  To compile this driver as a module, choose M here: the module
-
 config TCP_CONG_CUBIC
 	tristate "CUBIC TCP"
 	default y