[NET]: Add const markers to various variables.

the patch below marks various variables const in net/; the goal is to
move them to the .rodata section so that they can't false-share
cachelines with things that get written to, as well as potentially
helping gcc a bit with optimisations.  (these were found using a gcc
patch to warn about such variables)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index a65e508..0d7dc66 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -98,7 +98,7 @@
 }
 
 /* snmp items */
-static struct snmp_mib snmp4_ipstats_list[] = {
+static const struct snmp_mib snmp4_ipstats_list[] = {
 	SNMP_MIB_ITEM("InReceives", IPSTATS_MIB_INRECEIVES),
 	SNMP_MIB_ITEM("InHdrErrors", IPSTATS_MIB_INHDRERRORS),
 	SNMP_MIB_ITEM("InAddrErrors", IPSTATS_MIB_INADDRERRORS),
@@ -119,7 +119,7 @@
 	SNMP_MIB_SENTINEL
 };
 
-static struct snmp_mib snmp4_icmp_list[] = {
+static const struct snmp_mib snmp4_icmp_list[] = {
 	SNMP_MIB_ITEM("InMsgs", ICMP_MIB_INMSGS),
 	SNMP_MIB_ITEM("InErrors", ICMP_MIB_INERRORS),
 	SNMP_MIB_ITEM("InDestUnreachs", ICMP_MIB_INDESTUNREACHS),
@@ -149,7 +149,7 @@
 	SNMP_MIB_SENTINEL
 };
 
-static struct snmp_mib snmp4_tcp_list[] = {
+static const struct snmp_mib snmp4_tcp_list[] = {
 	SNMP_MIB_ITEM("RtoAlgorithm", TCP_MIB_RTOALGORITHM),
 	SNMP_MIB_ITEM("RtoMin", TCP_MIB_RTOMIN),
 	SNMP_MIB_ITEM("RtoMax", TCP_MIB_RTOMAX),
@@ -167,7 +167,7 @@
 	SNMP_MIB_SENTINEL
 };
 
-static struct snmp_mib snmp4_udp_list[] = {
+static const struct snmp_mib snmp4_udp_list[] = {
 	SNMP_MIB_ITEM("InDatagrams", UDP_MIB_INDATAGRAMS),
 	SNMP_MIB_ITEM("NoPorts", UDP_MIB_NOPORTS),
 	SNMP_MIB_ITEM("InErrors", UDP_MIB_INERRORS),
@@ -175,7 +175,7 @@
 	SNMP_MIB_SENTINEL
 };
 
-static struct snmp_mib snmp4_net_list[] = {
+static const struct snmp_mib snmp4_net_list[] = {
 	SNMP_MIB_ITEM("SyncookiesSent", LINUX_MIB_SYNCOOKIESSENT),
 	SNMP_MIB_ITEM("SyncookiesRecv", LINUX_MIB_SYNCOOKIESRECV),
 	SNMP_MIB_ITEM("SyncookiesFailed", LINUX_MIB_SYNCOOKIESFAILED),