style: Clean up parsing of UnicodeRange.

Differential Revision: https://phabricator.services.mozilla.com/D76330

components/style/parser.rs

@@ -208,10 +208,7 @@ where
 }
 
 impl Parse for UnicodeRange {
-    fn parse<'i, 't>(
+    fn parse<'i, 't>(_: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
-        _context: &ParserContext,
+        Ok(UnicodeRange::parse(input)?)
-        input: &mut Parser<'i, 't>,
-    ) -> Result<Self, ParseError<'i>> {
-        UnicodeRange::parse(input).map_err(|e| e.into())
     }
 }