string.c: fix types

* string.c (id_normalize, id_normalized_p): fix types, IDs should
  be ID.

* string.c (unicode_normalize_common): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58575 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

string.c

@@ -9584,12 +9584,12 @@ str_scrub_bang(int argc, VALUE *argv, VALUE str)
     return str;
 }
 
-static VALUE id_normalize;
+static ID id_normalize;
-static VALUE id_normalized_p;
+static ID id_normalized_p;
 static VALUE mUnicodeNormalize;
 
 static VALUE
-unicode_normalize_common(int argc, VALUE *argv, VALUE str, VALUE id)
+unicode_normalize_common(int argc, VALUE *argv, VALUE str, ID id)
 {
     static int UnicodeNormalizeRequired = 0;