[IPV4]: Make ip_tos2prio const.

Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/route.h

@@ -135,7 +135,7 @@ static inline void ip_rt_put(struct rtable * rt)
 
 #define IPTOS_RT_MASK	(IPTOS_TOS_MASK & ~3)
 
-extern __u8 ip_tos2prio[16];
+extern const __u8 ip_tos2prio[16];
 
 static inline char rt_tos2priority(u8 tos)
 {

net/ipv4/route.c

@@ -167,7 +167,7 @@ static struct dst_ops ipv4_dst_ops = {
 
 #define ECN_OR_COST(class)	TC_PRIO_##class
 
-__u8 ip_tos2prio[16] = {
+const __u8 ip_tos2prio[16] = {
 	TC_PRIO_BESTEFFORT,
 	ECN_OR_COST(FILLER),
 	TC_PRIO_BESTEFFORT,