Move PResult and ParseError under syn::synom
diff --git a/src/expr.rs b/src/expr.rs
index 5c46423..f8adefb 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -698,7 +698,7 @@
     use cursor::Cursor;
     #[cfg(feature = "full")]
     use parse_error;
-    use PResult;
+    use synom::PResult;
 
     // When we're parsing expressions which occur before blocks, like in an if
     // statement's condition, we cannot parse a struct literal.