[Snek] [keith-packard/snek] 53a9c8: Remove unused 'FL_MINUS' flag in strtof

[Keith Packard]

  Branch: refs/heads/main
  Home:   https://github.com/keith-packard/snek
  Commit: 53a9c819d27a1b975545350d24622bf1134b8929
      https://github.com/keith-packard/snek/commit/53a9c819d27a1b975545350d24622bf1134b8929
  Author: Keith Packard <keithp at keithp.com>
  Date:   2021-03-27 (Sat, 27 Mar 2021)

  Changed paths:
    M snek-strtof.c

  Log Message:
  -----------
  Remove unused 'FL_MINUS' flag in strtof

The lexer leaves the unary minus to the parser, so strtof will never
get a string with a sign. That code has been removed, but the flag was
left hanging around unused.

Signed-off-by: Keith Packard <keithp at keithp.com>