can't start chibi-scheme-static if shared object exist in default path

[chk-jxcn]

If shared object exist, start chibi-scheme-static show follow error:

ERROR: couldn't find builtin library: "/usr/local/lib/chibi/srfi/69/hash.so"

Maybe could skip function file_exists_p if sexp_find_static_library fail and path end with ".so" and static compiled.

    if (sexp_find_static_library(path) || file_exists_p(path, buf))
      return path;
    free(path);