kernel: Allow to clear domain in inet_db api
kernel: Allow to clear domain in inet_db api

If we do not allow this, we need to change the inet_res_SUITE
testcase so that it knows how to cleanup the domain after
running.

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