handle missing <net/if_dl.h> on Linux, reported by xiaolei zhang <win_hate@163.com>
handle missing <net/if_dl.h> on Linux, reported by xiaolei zhang <win_hate@163.com>


git-svn-id: 935794000d934034fad4bb4152be248a7507e5ff@610 0c474577-fa26-0410-a966-bdb198e94e9e

hellais/libdnet,hellais/libdnet,hellais/libdnet,hellais/libdnet