wallet: refactor: inline function ReadOrderPos()
wallet: refactor: inline function ReadOrderPos()

Since accounts were removed in commit c9c32e6b844fc79467b7e24c6c916142a0d08484,
this function is only called at one place and thus can be as well inlined. Also,
avoid a duplicate lookup by using the find() method and dereference, instead of
calling count() and operator[].

anditto/bitcoin,jambolo/bitcoin,jlopp/statoshi,dscotese/bitcoin,tecnovert/particl-core,mm-s/bitcoin,mm-s/bitcoin,AkioNak/bitcoin,sipsorcery/bitcoin,prusnak/bitcoin,GroestlCoin/bitcoin,GroestlCoin/GroestlCoin,andreaskern/bitcoin,particl/particl-core,fanquake/bitcoin,domob1812/namecore,namecoin/namecore,AkioNak/bitcoin,mruddy/bitcoin,prusnak/bitcoin,particl/particl-core,domob1812/bitcoin,Xekyo/bitcoin,bitcoinknots/bitcoin,kallewoof/bitcoin,sipsorcery/bitcoin,bitcoinsSG/bitcoin,dscotese/bitcoin,jlopp/statoshi,lateminer/bitcoin,Xekyo/bitcoin,bitcoin/bitcoin,kallewoof/bitcoin,namecoin/namecoin-core,dscotese/bitcoin,bitcoin/bitcoin,mruddy/bitcoin,namecoin/namecore,mruddy/bitcoin,andreaskern/bitcoin,MarcoFalke/bitcoin,jambolo/bitcoin,sipsorcery/bitcoin,fujicoin/fujicoin,pataquets/namecoin-core,lateminer/bitcoin,domob1812/namecore,anditto/bitcoin,instagibbs/bitcoin,sstone/bitcoin,lateminer/bitcoin,mm-s/bitcoin,tecnovert/particl-core,achow101/bitcoin,fujicoin/fujicoin,Xekyo/bitcoin,particl/particl-core,jamesob/bitcoin,GroestlCoin/GroestlCoin,namecoin/namecore,ajtowns/bitcoin,mm-s/bitcoin,MarcoFalke/bitcoin,jamesob/bitcoin,instagibbs/bitcoin,andreaskern/bitcoin,anditto/bitcoin,instagibbs/bitcoin,AkioNak/bitcoin,AkioNak/bitcoin,domob1812/namecore,namecoin/namecoin-core,namecoin/namecoin-core,bitcoinsSG/bitcoin,tecnovert/particl-core,anditto/bitcoin,ajtowns/bitcoin,ajtowns/bitcoin,kallewoof/bitcoin,domob1812/bitcoin,bitcoinknots/bitcoin,jambolo/bitcoin,mruddy/bitcoin,jlopp/statoshi,GroestlCoin/bitcoin,achow101/bitcoin,bitcoinsSG/bitcoin,AkioNak/bitcoin,fanquake/bitcoin,dscotese/bitcoin,jamesob/bitcoin,namecoin/namecoin-core,GroestlCoin/GroestlCoin,fujicoin/fujicoin,bitcoin/bitcoin,bitcoinknots/bitcoin,jambolo/bitcoin,sipsorcery/bitcoin,GroestlCoin/bitcoin,fanquake/bitcoin,achow101/bitcoin,anditto/bitcoin,pataquets/namecoin-core,particl/particl-core,kallewoof/bitcoin,bitcoin/bitcoin,sstone/bitcoin,jamesob/bitcoin,GroestlCoin/GroestlCoin,sipsorcery/bitcoin,kallewoof/bitcoin,pataquets/namecoin-core,bitcoinsSG/bitcoin,achow101/bitcoin,sstone/bitcoin,MarcoFalke/bitcoin,sipsorcery/bitcoin,dscotese/bitcoin,namecoin/namecoin-core,bitcoinsSG/bitcoin,jamesob/bitcoin,mm-s/bitcoin,dscotese/bitcoin,tecnovert/particl-core,jambolo/bitcoin,particl/particl-core,namecoin/namecore,Xekyo/bitcoin,fanquake/bitcoin,namecoin/namecoin-core,bitcoinknots/bitcoin,andreaskern/bitcoin,fanquake/bitcoin,fujicoin/fujicoin,andreaskern/bitcoin,pataquets/namecoin-core,mruddy/bitcoin,tecnovert/particl-core,anditto/bitcoin,bitcoinknots/bitcoin,lateminer/bitcoin,GroestlCoin/GroestlCoin,jambolo/bitcoin,ajtowns/bitcoin,prusnak/bitcoin,namecoin/namecore,lateminer/bitcoin,MarcoFalke/bitcoin,sstone/bitcoin,jlopp/statoshi,AkioNak/bitcoin,pataquets/namecoin-core,sstone/bitcoin,GroestlCoin/bitcoin,mruddy/bitcoin,jlopp/statoshi,prusnak/bitcoin,MarcoFalke/bitcoin,kallewoof/bitcoin,domob1812/bitcoin,GroestlCoin/GroestlCoin,fujicoin/fujicoin,pataquets/namecoin-core,instagibbs/bitcoin,particl/particl-core,instagibbs/bitcoin,ajtowns/bitcoin,achow101/bitcoin,namecoin/namecore,domob1812/namecore,GroestlCoin/bitcoin,jlopp/statoshi,bitcoinsSG/bitcoin,tecnovert/particl-core,bitcoin/bitcoin,achow101/bitcoin,MarcoFalke/bitcoin,domob1812/namecore,prusnak/bitcoin,bitcoin/bitcoin,sstone/bitcoin,Xekyo/bitcoin,fujicoin/fujicoin,mm-s/bitcoin,ajtowns/bitcoin,prusnak/bitcoin,domob1812/bitcoin,fanquake/bitcoin,Xekyo/bitcoin,domob1812/namecore,instagibbs/bitcoin,jamesob/bitcoin,andreaskern/bitcoin,domob1812/bitcoin,GroestlCoin/bitcoin,domob1812/bitcoin,lateminer/bitcoin