kernel: Eliminate warnings in C code in tests
kernel: Eliminate warnings in C code in tests

Apple Clang 12 in Xcode 12 reports an error for the use of a
function without a declaration.

emacsmirror/erlang,isvilen/otp,erlang/otp,erlang/otp,jj1bdx/otp,dgud/otp,bjorng/otp,ferd/otp,lrascao/otp,dumbbell/otp,uabboli/otp,lrascao/otp,getong/otp,potatosalad/otp,uabboli/otp,dumbbell/otp,ferd/otp,lrascao/otp,rlipscombe/otp,uabboli/otp,potatosalad/otp,isvilen/otp,g-andrade/otp,g-andrade/otp,vinoski/otp,ferd/otp,rlipscombe/otp,rlipscombe/otp,lrascao/otp,getong/otp,isvilen/otp,emacsmirror/erlang,rlipscombe/otp,dumbbell/otp,bjorng/otp,mikpe/otp,potatosalad/otp,dgud/otp,emacsmirror/erlang,dumbbell/otp,ferd/otp,lrascao/otp,isvilen/otp,lrascao/otp,dgud/otp,getong/otp,dgud/otp,vinoski/otp,isvilen/otp,mikpe/otp,vinoski/otp,potatosalad/otp,bjorng/otp,vinoski/otp,mikpe/otp,jj1bdx/otp,mikpe/otp,lrascao/otp,emacsmirror/erlang,rlipscombe/otp,g-andrade/otp,jj1bdx/otp,getong/otp,jj1bdx/otp,emacsmirror/erlang,erlang/otp,rlipscombe/otp,bjorng/otp,getong/otp,rlipscombe/otp,uabboli/otp,vinoski/otp,lrascao/otp,uabboli/otp,erlang/otp,emacsmirror/erlang,vinoski/otp,potatosalad/otp,bjorng/otp,mikpe/otp,bjorng/otp,emacsmirror/erlang,emacsmirror/erlang,mikpe/otp,potatosalad/otp,potatosalad/otp,erlang/otp,bjorng/otp,getong/otp,ferd/otp,g-andrade/otp,isvilen/otp,getong/otp,isvilen/otp,dumbbell/otp,emacsmirror/erlang,potatosalad/otp,dumbbell/otp,erlang/otp,g-andrade/otp,vinoski/otp,dgud/otp,dumbbell/otp,ferd/otp,mikpe/otp,dgud/otp,g-andrade/otp,dumbbell/otp,getong/otp,ferd/otp,uabboli/otp,rlipscombe/otp,isvilen/otp,dgud/otp,jj1bdx/otp,erlang/otp,bjorng/otp,mikpe/otp,dgud/otp,dgud/otp,mikpe/otp,g-andrade/otp,erlang/otp,vinoski/otp,bjorng/otp,jj1bdx/otp,ferd/otp,g-andrade/otp,jj1bdx/otp,jj1bdx/otp,uabboli/otp,dgud/otp,emacsmirror/erlang,erlang/otp,isvilen/otp,jj1bdx/otp,potatosalad/otp,bjorng/otp,vinoski/otp,isvilen/otp,mikpe/otp,g-andrade/otp,getong/otp,dumbbell/otp,jj1bdx/otp,erlang/otp,vinoski/otp,uabboli/otp,g-andrade/otp,potatosalad/otp,dumbbell/otp,ferd/otp,rlipscombe/otp,uabboli/otp,getong/otp,lrascao/otp,rlipscombe/otp