libbb: nuke BB_GETOPT_ERROR, always die if there are mutually exclusive options

libbb: nuke BB_GETOPT_ERROR, always die if there are mutually exclusive options
find_pair                                            164     180     +16
passwd_main                                         1222    1230      +8
display_speed                                         91      96      +5
msh_main                                            1335    1339      +4
qrealloc                                              38      36      -2
refresh                                             1190    1182      -8
cut_main                                             543     532     -11
sendCgi                                             1807    1794     -13
getopt32                                            1063    1045     -18
arith                                               2077    2030     -47
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(add/remove: 0/0 grow/shrink: 4/6 up/down: 33/-99)            Total: -66 bytes
   text    data     bss     dec     hex filename
 781548    1168   11900  794616   c1ff8 busybox_old
 781452    1168   11900  794520   c1f98 busybox_unstripped