r0 = socket$inet6_tcp(0xa, 0x1, 0x0)
ioctl$sock_inet6_SIOCDELRT(r0, 0x890c, &(0x7f0000000200)={@private1, @private2, @mcast1, 0x0, 0x7, 0x0, 0x0, 0x0, 0x1040000})