ipv6:remove useless check

After switch (rthdr->type) {...},the check below is completely useless.Because:
if the type is 2,then hdrlen must be 2 and segments_left must be 1,clearly the
check is redundant;if the type is not 2,then goto sticky_done,the check is useless
too.
Signed-off-by: NYang Hongyang <yanghy@cn.fujitsu.com>
Reviewed-by: NShan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/ipv6_sockglue.c

@@ -380,10 +380,6 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 			default:
 				goto sticky_done;
 			}
-
-			if ((rthdr->hdrlen & 1) ||
-			    (rthdr->hdrlen >> 1) != rthdr->segments_left)
-				goto sticky_done;
 		}
 
 		retv = 0;