[NET]: Fix sparse warnings

Of this type, mostly:

CHECK   net/ipv6/netfilter.c
net/ipv6/netfilter.c:96:12: warning: symbol 'ipv6_netfilter_init' was not declared. Should it be static?
net/ipv6/netfilter.c:101:6: warning: symbol 'ipv6_netfilter_fini' was not declared. Should it be static?

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/802/p8023.c

@@ -20,6 +20,7 @@
 #include <linux/skbuff.h>
 
 #include <net/datalink.h>
+#include <net/p8022.h>
 
 /*
  *	Place an 802.3 header on a packet. The driver will do the mac

net/802/sysctl_net_802.c

@@ -10,9 +10,10 @@
  *		2 of the License, or (at your option) any later version.
  */
 
-#include <linux/mm.h>
-#include <linux/sysctl.h>
 #include <linux/config.h>
+#include <linux/mm.h>
+#include <linux/if_tr.h>
+#include <linux/sysctl.h>
 
 #ifdef CONFIG_TR
 extern int sysctl_tr_rif_timeout;