[NETFILTER]: Use const in struct xt_match, xt_target, xt_table

Signed-off-by: Jan Engelhardt <[e-mail]>
Signed-off-by: Patrick McHardy <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/netfilter/x_tables.h

···
 	/* Free to use by each match */
 	unsigned long data;
 
-	char *table;
+	const char *table;
 	unsigned int matchsize;
 	unsigned int compatsize;
 	unsigned int hooks;
···
 	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
 	struct module *me;
 
-	char *table;
+	const char *table;
 	unsigned int targetsize;
 	unsigned int compatsize;
 	unsigned int hooks;
···
 	struct list_head list;
 
 	/* A unique name... */
-	char name[XT_TABLE_MAXNAMELEN];
+	const char name[XT_TABLE_MAXNAMELEN];
 
 	/* What hooks you will enter on */
 	unsigned int valid_hooks;

net/ipv4/netfilter/ip_tables.c

···
 			 unsigned int hook,
 			 const struct net_device *in,
 			 const struct net_device *out,
-			 char *tablename,
+			 const char *tablename,
 			 struct xt_table_info *private,
 			 struct ipt_entry *e)
 {

net/ipv6/netfilter/ip6_tables.c

···
 			 unsigned int hook,
 			 const struct net_device *in,
 			 const struct net_device *out,
-			 char *tablename,
+			 const char *tablename,
 			 struct xt_table_info *private,
 			 struct ip6t_entry *e)
 {