[dts] fix an issue in ipv4_reassembly

[Fan, ChangruX]

    Hi  Liu, Yong

          The case send_4K_frames_split_in_7_and_4K_maxflows which in ipv4_reassembly is failed on freebsd10.1.

I think the reason is that, in the function  set_max_num_of_fragments it's set with an error configuration file.

Please check the patch.

Thank,
changru