net: some fixes

[Motoya Kurotsu <kurotsu at allied-telesis dot co dot jp>]

Hi, all;

The attachment fixes the following problems;

    1) In bsd_tcpip stack, m_mballoc() may be called in non-blocking mode, 
       i.e. with M_DONTWAIT. See the definitions of MGET and MGETHDR. 
       However m_mballoc() always call cyg_net_mbuf_alloc() in 
       blocking mode with the second argument zero.
    2) In bsd_tcpip stack, show_net_times() requires the variable 
       'stats_in_cksum' but it actually doesn't exist.
    3) In both of bsd_tcpip stack and tcpip stack, show_net_stats()
       may cause zero division.

Motoya Kurotsu
Allied Telesis K.K.

Attachment: net.patch
Description: Text document