py/objstr: Remove unnecessary "sign" variable in formatting code.

Author: dpgeorge

py/objstr.c

@@ -1078,7 +1078,6 @@ STATIC vstr_t mp_obj_str_format_helper(const char *str, const char *top, int *ar
  arg = mp_obj_new_str_from_vstr(&mp_type_str, &arg_vstr);
  }
 
- char sign = '\0';
  char fill = '\0';
  char align = '\0';
  int width = -1;
@@ -1114,7 +1113,7 @@ STATIC vstr_t mp_obj_str_format_helper(const char *str, const char *top, int *ar
  } else if (*s == ' ') {
  flags |= PF_FLAG_SPACE_SIGN;
  }
- sign = *s++;
+ s++;
  }
  if (*s == '#') {
  flags |= PF_FLAG_SHOW_PREFIX;
@@ -1160,7 +1159,7 @@ STATIC vstr_t mp_obj_str_format_helper(const char *str, const char *top, int *ar
  fill = ' ';
  }
 
- if (sign) {
+ if (flags & (PF_FLAG_SHOW_SIGN | PF_FLAG_SPACE_SIGN)) {
  if (type == 's') {
  if (MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE) {
  terse_str_format_value_error();
@@ -1176,8 +1175,6 @@ STATIC vstr_t mp_obj_str_format_helper(const char *str, const char *top, int *ar
  "sign not allowed with integer format specifier 'c'");
  }
  }
- } else {
- sign = '-';
  }
 
  switch (align) {