net: constify MIB name tables

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index f25542c..1b09a6d 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -127,8 +127,8 @@
 	SNMP_MIB_SENTINEL
 };
 
-static struct {
-	char *name;
+static const struct {
+	const char *name;
 	int index;
 } icmpmibmap[] = {
 	{ "DestUnreachs", ICMP_DEST_UNREACH },