db: fix problem with initialization of a column family
db: fix problem with initialization of a column family

We should only call column_family::start after the checks because
if a check failed, column_family would be destroyed without
column_family::stop being called first, and that would lead to
a problem, such as _compaction_done future not being resolved.

Signed-off-by: Raphael S. Carvalho <1e2942cea40e3b4d2162dfcd9e53e41c05a84d22@cloudius-systems.com>

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