m4/acinclude.m4: write ETH_P_ALL check as function body, not function definition#110

ofalk merged 2 commits intoofalk:develofalk/libdnet:develfrom

robertkirkman:fix-autotools-clang-pf-packetrobertkirkman/libdnet:fix-autotools-clang-pf-packetCopy head branch name to clipboard