opensc-explorer: re-factor do_find()
opensc-explorer: re-factor do_find()

* set default values for variables at declaration time
* use sizeof(fid) instead of magic number
* use braces after sizeof, i.e. sizeof(X) instead of sizeof X
* start error message with upper-case letter

OpenSC/OpenSC,rickyepoderi/OpenSC,Jakuje/OpenSC,AktivCo/OpenSC,philipWendland/OpenSC,dengert/OpenSC,Jakuje/OpenSC,fabled/OpenSC,LudovicRousseau/OpenSC,metsma/OpenSC,philipWendland/OpenSC,frankmorgner/OpenSC,Jakuje/OpenSC,frankmorgner/OpenSC,metsma/OpenSC,mouse07410/OpenSC,mouse07410/OpenSC,fabled/OpenSC,Jakuje/OpenSC,LudovicRousseau/OpenSC,mouse07410/OpenSC,fabled/OpenSC,hongquan/OpenSC-main,philipWendland/OpenSC,LudovicRousseau/OpenSC,dengert/OpenSC,frankmorgner/OpenSC,rickyepoderi/OpenSC,AktivCo/OpenSC,OpenSC/OpenSC,frankmorgner/OpenSC,hongquan/OpenSC-main,fabled/OpenSC,AktivCo/OpenSC,rickyepoderi/OpenSC,metsma/OpenSC,hongquan/OpenSC-main,OpenSC/OpenSC,dengert/OpenSC