[NET]: Fix some userland header bustage.

include/linux/netfilter.h

@@ -10,6 +10,7 @@
 #include <linux/wait.h>
 #include <linux/list.h>
 #endif
+#include <linux/compiler.h>
 
 /* Responses from hook functions. */
 #define NF_DROP 0

include/linux/netfilter_arp/arp_tables.h

@@ -16,7 +16,7 @@
 #include <linux/if_arp.h>
 #include <linux/skbuff.h>
 #endif
-
+#include <linux/compiler.h>
 #include <linux/netfilter_arp.h>
 
 #define ARPT_FUNCTION_MAXNAMELEN 30

include/linux/netfilter_ipv4/ip_tables.h

@@ -22,6 +22,7 @@
 #include <linux/ip.h>
 #include <linux/skbuff.h>
 #endif
+#include <linux/compiler.h>
 #include <linux/netfilter_ipv4.h>
 
 #define IPT_FUNCTION_MAXNAMELEN 30
@@ -336,8 +337,8 @@ ipt_get_target(struct ipt_entry *e)
 /*
  *	Main firewall chains definitions and global var's definitions.
  */
-static DECLARE_MUTEX(ipt_mutex);
 #ifdef __KERNEL__
+static DECLARE_MUTEX(ipt_mutex);
 
 #include <linux/init.h>
 extern void ipt_init(void) __init;

include/linux/netfilter_ipv6/ip6_tables.h

@@ -22,6 +22,7 @@
 #include <linux/ipv6.h>
 #include <linux/skbuff.h>
 #endif
+#include <linux/compiler.h>
 #include <linux/netfilter_ipv6.h>
 
 #define IP6T_FUNCTION_MAXNAMELEN 30
@@ -106,7 +107,9 @@ struct ip6t_counters
 	u_int64_t pcnt, bcnt;			/* Packet and byte counters */
 };
 
+#ifdef __KERNEL__
 static DECLARE_MUTEX(ip6t_mutex);
+#endif
 
 /* Values for "flag" field in struct ip6t_ip6 (general ip6 structure). */
 #define IP6T_F_PROTO		0x01	/* Set if rule cares about upper