parser: remove unneccessary wrapping of return value in parse_extern()

Author: matthiaskrgr

compiler/rustc_parse/src/parser/item.rs

@@ -1679,7 +1679,7 @@ impl<'a> Parser<'a> {
         let constness = self.parse_constness();
         let asyncness = self.parse_asyncness();
         let unsafety = self.parse_unsafety();
-        let ext = self.parse_extern()?;
+        let ext = self.parse_extern();
 
         if let Async::Yes { span, .. } = asyncness {
             self.ban_async_in_2015(span);

compiler/rustc_parse/src/parser/mod.rs

@@ -1202,12 +1202,8 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses `extern string_literal?`.
-    fn parse_extern(&mut self) -> PResult<'a, Extern> {
-        Ok(if self.eat_keyword(kw::Extern) {
-            Extern::from_abi(self.parse_abi())
-        } else {
-            Extern::None
-        })
+    fn parse_extern(&mut self) -> Extern {
+        if self.eat_keyword(kw::Extern) { Extern::from_abi(self.parse_abi()) } else { Extern::None }
     }
 
     /// Parses a string literal as an ABI spec.