validation: remove redundant check on pindex
validation: remove redundant check on pindex

This removes a conditional that checks if pindex is equal to nullptr.
This check is redundant because the branch where pindex is set returns at an earlier time. Additionaly, The independence of the earlier and later pindex is made clearer.

domob1812/bitcoin,fanquake/bitcoin,AkioNak/bitcoin,n1bor/bitcoin,domob1812/bitcoin,ajtowns/bitcoin,jambolo/bitcoin,sipsorcery/bitcoin,n1bor/bitcoin,MeshCollider/bitcoin,rnicoll/bitcoin,anditto/bitcoin,JeremyRubin/bitcoin,yenliangl/bitcoin,domob1812/namecore,kallewoof/bitcoin,jamesob/bitcoin,mruddy/bitcoin,tecnovert/particl-core,sstone/bitcoin,prusnak/bitcoin,MarcoFalke/bitcoin,pstratem/bitcoin,instagibbs/bitcoin,apoelstra/bitcoin,bitcoinknots/bitcoin,bitcoinsSG/bitcoin,instagibbs/bitcoin,practicalswift/bitcoin,particl/particl-core,bitcoinsSG/bitcoin,yenliangl/bitcoin,namecoin/namecoin-core,rnicoll/bitcoin,mm-s/bitcoin,GroestlCoin/bitcoin,MeshCollider/bitcoin,domob1812/bitcoin,jlopp/statoshi,achow101/bitcoin,anditto/bitcoin,AkioNak/bitcoin,fujicoin/fujicoin,fujicoin/fujicoin,dscotese/bitcoin,namecoin/namecore,lateminer/bitcoin,jamesob/bitcoin,andreaskern/bitcoin,andreaskern/bitcoin,JeremyRubin/bitcoin,domob1812/namecore,lateminer/bitcoin,MarcoFalke/bitcoin,lateminer/bitcoin,fujicoin/fujicoin,particl/particl-core,n1bor/bitcoin,ElementsProject/elements,jlopp/statoshi,fujicoin/fujicoin,rnicoll/bitcoin,tecnovert/particl-core,dscotese/bitcoin,ajtowns/bitcoin,Xekyo/bitcoin,GroestlCoin/GroestlCoin,prusnak/bitcoin,domob1812/bitcoin,jamesob/bitcoin,n1bor/bitcoin,bitcoin/bitcoin,prusnak/bitcoin,qtumproject/qtum,sipsorcery/bitcoin,fanquake/bitcoin,GroestlCoin/bitcoin,particl/particl-core,GroestlCoin/bitcoin,Sjors/bitcoin,bitcoin/bitcoin,mm-s/bitcoin,anditto/bitcoin,yenliangl/bitcoin,dscotese/bitcoin,bitcoinsSG/bitcoin,dscotese/bitcoin,bitcoinsSG/bitcoin,MeshCollider/bitcoin,kallewoof/bitcoin,namecoin/namecore,jambolo/bitcoin,kallewoof/bitcoin,mruddy/bitcoin,bitcoin/bitcoin,practicalswift/bitcoin,jambolo/bitcoin,tecnovert/particl-core,pataquets/namecoin-core,instagibbs/bitcoin,apoelstra/bitcoin,rnicoll/bitcoin,qtumproject/qtum,Xekyo/bitcoin,GroestlCoin/GroestlCoin,tecnovert/particl-core,tecnovert/particl-core,pstratem/bitcoin,MarcoFalke/bitcoin,Xekyo/bitcoin,pataquets/namecoin-core,sipsorcery/bitcoin,lateminer/bitcoin,practicalswift/bitcoin,jlopp/statoshi,Sjors/bitcoin,kallewoof/bitcoin,achow101/bitcoin,GroestlCoin/bitcoin,bitcoinsSG/bitcoin,pataquets/namecoin-core,namecoin/namecoin-core,kallewoof/bitcoin,apoelstra/bitcoin,bitcoin/bitcoin,jambolo/bitcoin,prusnak/bitcoin,achow101/bitcoin,yenliangl/bitcoin,mruddy/bitcoin,Sjors/bitcoin,GroestlCoin/bitcoin,mm-s/bitcoin,particl/particl-core,pstratem/bitcoin,GroestlCoin/bitcoin,andreaskern/bitcoin,namecoin/namecoin-core,AkioNak/bitcoin,JeremyRubin/bitcoin,ElementsProject/elements,andreaskern/bitcoin,practicalswift/bitcoin,AkioNak/bitcoin,GroestlCoin/GroestlCoin,JeremyRubin/bitcoin,pataquets/namecoin-core,anditto/bitcoin,mm-s/bitcoin,bitcoinknots/bitcoin,MarcoFalke/bitcoin,sstone/bitcoin,andreaskern/bitcoin,n1bor/bitcoin,fanquake/bitcoin,fujicoin/fujicoin,sstone/bitcoin,ElementsProject/elements,namecoin/namecoin-core,bitcoinknots/bitcoin,jamesob/bitcoin,lateminer/bitcoin,particl/particl-core,ajtowns/bitcoin,AkioNak/bitcoin,practicalswift/bitcoin,domob1812/namecore,jlopp/statoshi,qtumproject/qtum,sipsorcery/bitcoin,kallewoof/bitcoin,jlopp/statoshi,ajtowns/bitcoin,mruddy/bitcoin,domob1812/bitcoin,mm-s/bitcoin,mruddy/bitcoin,sipsorcery/bitcoin,AkioNak/bitcoin,pataquets/namecoin-core,apoelstra/bitcoin,MeshCollider/bitcoin,MeshCollider/bitcoin,dscotese/bitcoin,domob1812/bitcoin,achow101/bitcoin,instagibbs/bitcoin,jamesob/bitcoin,qtumproject/qtum,apoelstra/bitcoin,yenliangl/bitcoin,MarcoFalke/bitcoin,dscotese/bitcoin,pstratem/bitcoin,jambolo/bitcoin,sstone/bitcoin,ajtowns/bitcoin,namecoin/namecore,MeshCollider/bitcoin,GroestlCoin/GroestlCoin,prusnak/bitcoin,bitcoinknots/bitcoin,apoelstra/bitcoin,domob1812/namecore,ElementsProject/elements,anditto/bitcoin,Xekyo/bitcoin,jamesob/bitcoin,rnicoll/bitcoin,jambolo/bitcoin,Sjors/bitcoin,mruddy/bitcoin,tecnovert/particl-core,JeremyRubin/bitcoin,instagibbs/bitcoin,fanquake/bitcoin,MarcoFalke/bitcoin,ElementsProject/elements,anditto/bitcoin,rnicoll/bitcoin,achow101/bitcoin,Xekyo/bitcoin,achow101/bitcoin,qtumproject/qtum,sstone/bitcoin,pataquets/namecoin-core,yenliangl/bitcoin,practicalswift/bitcoin,sipsorcery/bitcoin,qtumproject/qtum,Xekyo/bitcoin,jlopp/statoshi,namecoin/namecore,JeremyRubin/bitcoin,domob1812/namecore,mm-s/bitcoin,bitcoin/bitcoin,Sjors/bitcoin,fanquake/bitcoin,fanquake/bitcoin,pstratem/bitcoin,bitcoinsSG/bitcoin,sstone/bitcoin,namecoin/namecoin-core,pstratem/bitcoin,GroestlCoin/GroestlCoin,bitcoinknots/bitcoin,ajtowns/bitcoin,n1bor/bitcoin,qtumproject/qtum,lateminer/bitcoin,andreaskern/bitcoin,prusnak/bitcoin,bitcoin/bitcoin,particl/particl-core,namecoin/namecore,domob1812/namecore,ElementsProject/elements,GroestlCoin/GroestlCoin,fujicoin/fujicoin,namecoin/namecore,instagibbs/bitcoin,namecoin/namecoin-core