parse.y: Remove unneeded var_field_1 trick

I thought this trick was needed because the result of var_field was
passed to different arguments, as follows:

```
$1 = var_field(p, $1);
$$ = backref_assign_error(p, $1, $1, &@$);
```

Currently the DSL supports that one result is passed to one argument.

However, after the refactoring, I found that `backref_assign_error`
uses only one `$1`.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61979 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

0 files changed, 0 insertions, 0 deletions