decnet: remove duplicated include from dn_table.c

Remove duplicated include.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/decnet/dn_table.c

@@ -19,7 +19,6 @@
 #include <linux/sockios.h>
 #include <linux/init.h>
 #include <linux/skbuff.h>
-#include <net/netlink.h>
 #include <linux/rtnetlink.h>
 #include <linux/proc_fs.h>
 #include <linux/netdevice.h>