sstables: add function to set generation
sstables: add function to set generation

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

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