opensc-explorer: replace magic numbers by SC_MAX_PIN_SIZE
opensc-explorer: replace magic numbers by SC_MAX_PIN_SIZE

Replace magic numbers, used as size of PIN-type buffers,
with the symbolic constant SC_MAX_PIN_SIZE, fixing
- readability / understandability
- too small sizes (e.g. for GnuPG cards)

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