validation: remove snapshot datadirs upon validation failure
validation: remove snapshot datadirs upon validation failure

If a UTXO snapshot fails to validate, don't leave the resulting datadir
on disk as this will confuse initialization on next startup and we'll
get an assertion error.

bitcoinsSG/bitcoin,fanquake/bitcoin,lateminer/bitcoin,tecnovert/particl-core,sipsorcery/bitcoin,jambolo/bitcoin,jambolo/bitcoin,sstone/bitcoin,lateminer/bitcoin,bitcoinsSG/bitcoin,tecnovert/particl-core,kallewoof/bitcoin,mruddy/bitcoin,namecoin/namecoin-core,namecoin/namecoin-core,mruddy/bitcoin,jambolo/bitcoin,sstone/bitcoin,kallewoof/bitcoin,bitcoin/bitcoin,particl/particl-core,mruddy/bitcoin,lateminer/bitcoin,mruddy/bitcoin,lateminer/bitcoin,fanquake/bitcoin,kallewoof/bitcoin,particl/particl-core,fanquake/bitcoin,bitcoin/bitcoin,AkioNak/bitcoin,mruddy/bitcoin,namecoin/namecoin-core,kallewoof/bitcoin,bitcoinsSG/bitcoin,sipsorcery/bitcoin,tecnovert/particl-core,bitcoinsSG/bitcoin,AkioNak/bitcoin,bitcoinsSG/bitcoin,jambolo/bitcoin,AkioNak/bitcoin,jambolo/bitcoin,bitcoin/bitcoin,kallewoof/bitcoin,sstone/bitcoin,bitcoinsSG/bitcoin,bitcoin/bitcoin,fanquake/bitcoin,sstone/bitcoin,bitcoin/bitcoin,tecnovert/particl-core,sstone/bitcoin,mruddy/bitcoin,AkioNak/bitcoin,tecnovert/particl-core,fanquake/bitcoin,particl/particl-core,particl/particl-core,sipsorcery/bitcoin,bitcoin/bitcoin,namecoin/namecoin-core,namecoin/namecoin-core,fanquake/bitcoin,AkioNak/bitcoin,sipsorcery/bitcoin,kallewoof/bitcoin,sipsorcery/bitcoin,sipsorcery/bitcoin,lateminer/bitcoin,particl/particl-core,tecnovert/particl-core,lateminer/bitcoin,namecoin/namecoin-core,jambolo/bitcoin,sstone/bitcoin,particl/particl-core,AkioNak/bitcoin