bc: simplify input pointer manipulation while lexing

function                                             old     new   delta
bc_lex_name                                           70      68      -2
zbc_lex_number                                       177     174      -3
bc_vm_init                                           679     676      -3
bc_lex_whitespace                                     42      39      -3
zbc_parse_text_init                                   55      51      -4
bc_lex_lineComment                                    37      29      -8
bc_lex_assign                                         34      26      -8
zbc_lex_next                                        2039    1965     -74
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/8 up/down: 0/-105)           Total: -105 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1 file changed