net: fix const correctness for byte-order functions
net: fix const correctness for byte-order functions

The byte-order functions were changed not to do in-place conversions,
but they still accept non-const inputs, although they do not modify them.
This can make them harder to use in some cases.

Fix by marking the inputs const.

shyamalschandra/seastar,cloudius-systems/seastar,justintung/scylla,victorbriz/scylla,rentongzhang/scylla,eklitzke/scylla,dreamsxin/seastar,syuu1228/seastar,raphaelsc/seastar,xtao/seastar,printedheart/seastar,scylladb/seastar,guiquanz/scylla,norcimo5/seastar,scylladb/seastar,acbellini/scylla,duarten/scylla,chunshengster/seastar,raphaelsc/seastar,scylladb/scylla,raphaelsc/scylla,norcimo5/seastar,kangkot/scylla,scylladb/scylla,asias/scylla,sjperkins/seastar,slivne/seastar,linearregression/seastar,raphaelsc/scylla,syuu1228/seastar,kjniemi/seastar,shyamalschandra/seastar,acbellini/scylla,flashbuckets/seastar,avikivity/scylla,avikivity/scylla,avikivity/seastar,tempbottle/seastar,bowlofstew/scylla,eklitzke/scylla,dwdm/seastar,stamhe/seastar,guiquanz/scylla,acbellini/seastar,mixja/seastar,dwdm/scylla,leejir/seastar,stamhe/scylla,scylladb/scylla-seastar,koolhazz/seastar,respu/scylla,linearregression/seastar,shaunstanislaus/scylla,acbellini/seastar,bowlofstew/seastar,joerg84/seastar,anzihenry/seastar,cloudius-systems/seastar,tempbottle/scylla,wildinto/seastar,slivne/seastar,mixja/seastar,dwdm/seastar,dwdm/seastar,kangkot/scylla,tempbottle/scylla,hongliangzhao/seastar,leejir/seastar,avikivity/seastar,linearregression/seastar,rentongzhang/scylla,flashbuckets/seastar,justintung/scylla,raphaelsc/seastar,scylladb/scylla,scylladb/scylla,norcimo5/seastar,rluta/scylla,justintung/scylla,joerg84/seastar,dreamsxin/seastar,scylladb/seastar,anzihenry/seastar,duarten/scylla,xtao/seastar,koolhazz/seastar,senseb/scylla,bowlofstew/seastar,stamhe/seastar,capturePointer/scylla,wildinto/seastar,tempbottle/seastar,kjniemi/seastar,scylladb/scylla-seastar,gwicke/scylla,sjperkins/seastar,bowlofstew/scylla,flashbuckets/seastar,respu/scylla,capturePointer/scylla,cloudius-systems/seastar,acbellini/scylla,chunshengster/seastar,anzihenry/seastar,tempbottle/seastar,wildinto/scylla,phonkee/scylla,chunshengster/seastar,guiquanz/scylla,victorbriz/scylla,ducthangho/imdb,hongliangzhao/seastar,eklitzke/scylla,mixja/seastar,aruanruan/scylla,bzero/seastar,syuu1228/seastar,kjniemi/scylla,aruanruan/scylla,printedheart/seastar,jonathanleang/seastar,gwicke/scylla,tempbottle/scylla,bowlofstew/seastar,senseb/scylla,dwdm/scylla,gwicke/scylla,scylladb/scylla-seastar,dreamsxin/seastar,asias/scylla,slivne/seastar,stamhe/scylla,respu/scylla,jonathanleang/seastar,shaunstanislaus/scylla,asias/scylla,stamhe/scylla,rluta/scylla,phonkee/scylla,hongliangzhao/seastar,acbellini/seastar,shyamalschandra/seastar,printedheart/seastar,linearregression/scylla,shaunstanislaus/scylla,raphaelsc/scylla,rentongzhang/scylla,kjniemi/scylla,senseb/scylla,wildinto/seastar,sjperkins/seastar,wildinto/scylla,dwdm/scylla,phonkee/scylla,wildinto/scylla,capturePointer/scylla,glommer/scylla,avikivity/seastar,ducthangho/imdb,jonathanleang/seastar,ducthangho/imdb,leejir/seastar,bzero/seastar,duarten/scylla,linearregression/scylla,koolhazz/seastar,glommer/scylla,victorbriz/scylla,xtao/seastar,rluta/scylla,bowlofstew/scylla,stamhe/seastar,kjniemi/seastar,avikivity/scylla,linearregression/scylla,aruanruan/scylla,bzero/seastar,kangkot/scylla,kjniemi/scylla,glommer/scylla,joerg84/seastar