Import struct_span_err macro instead of prepending it

compiler/rustc_expand/src/expand.rs

@@ -18,7 +18,7 @@ use rustc_ast_pretty::pprust;
 use rustc_attr::{self as attr, is_builtin_attr, HasAttrs};
 use rustc_data_structures::map_in_place::MapInPlace;
 use rustc_data_structures::stack::ensure_sufficient_stack;
-use rustc_errors::{Applicability, PResult};
+use rustc_errors::{struct_span_err, Applicability, PResult};
 use rustc_feature::Features;
 use rustc_parse::parser::Parser;
 use rustc_parse::validate_attr;
@@ -542,7 +542,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
     fn error_derive_forbidden_on_non_adt(&self, derives: &[Path], item: &Annotatable) {
         let attr = self.cx.sess.find_by_name(item.attrs(), sym::derive);
         let span = attr.map_or(item.span(), |attr| attr.span);
-        let mut err = rustc_errors::struct_span_err!(
+        let mut err = struct_span_err!(
             self.cx.sess,
             span,
             E0774,