cxgb4: remove duplicated include from cxgb4_main.c

Remove duplicated include.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c

@@ -62,7 +62,6 @@
 #include <net/netevent.h>
 #include <net/addrconf.h>
 #include <net/bonding.h>
-#include <net/addrconf.h>
 #include <linux/uaccess.h>
 #include <linux/crash_dump.h>
 #include <net/udp_tunnel.h>