libbb: fix mishandling of "all argv are opts" in getopt32()

function                                             old     new   delta
top_main                                            1100    1095      -5
getopt32                                            1398    1361     -37
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(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-42)             Total: -42 bytes

2 files changed