cql3: Fix column identifier lookups
cql3: Fix column identifier lookups

We're looking up shared_ptr<column_identifier> type so make sure we
lookup by value, not by pointer.

Signed-off-by: Pekka Enberg <add4fcd06328a394f0ad91feda7ee057316dc5ed@cloudius-systems.com>

justintung/scylla,dwdm/scylla,stamhe/scylla,kjniemi/scylla,acbellini/scylla,duarten/scylla,asias/scylla,bowlofstew/scylla,stamhe/scylla,senseb/scylla,tempbottle/scylla,avikivity/scylla,shaunstanislaus/scylla,guiquanz/scylla,tempbottle/scylla,wildinto/scylla,tempbottle/scylla,kangkot/scylla,victorbriz/scylla,justintung/scylla,scylladb/scylla,rentongzhang/scylla,shaunstanislaus/scylla,dwdm/scylla,senseb/scylla,asias/scylla,acbellini/scylla,respu/scylla,kangkot/scylla,dwdm/scylla,rluta/scylla,kjniemi/scylla,rluta/scylla,raphaelsc/scylla,glommer/scylla,linearregression/scylla,kangkot/scylla,duarten/scylla,aruanruan/scylla,senseb/scylla,rluta/scylla,phonkee/scylla,justintung/scylla,rentongzhang/scylla,eklitzke/scylla,glommer/scylla,kjniemi/scylla,eklitzke/scylla,guiquanz/scylla,respu/scylla,aruanruan/scylla,raphaelsc/scylla,capturePointer/scylla,scylladb/scylla,victorbriz/scylla,shaunstanislaus/scylla,avikivity/scylla,aruanruan/scylla,raphaelsc/scylla,wildinto/scylla,respu/scylla,asias/scylla,scylladb/scylla,bowlofstew/scylla,victorbriz/scylla,phonkee/scylla,capturePointer/scylla,acbellini/scylla,duarten/scylla,gwicke/scylla,avikivity/scylla,wildinto/scylla,scylladb/scylla,linearregression/scylla,phonkee/scylla,linearregression/scylla,rentongzhang/scylla,glommer/scylla,gwicke/scylla,gwicke/scylla,bowlofstew/scylla,capturePointer/scylla,stamhe/scylla,eklitzke/scylla,guiquanz/scylla