rebased from master --squash this--

Author: DevinR528

clippy_lints/src/macro_use.rs

@@ -233,7 +233,9 @@ impl<'l, 'txc> LateLintPass<'l, 'txc> for MacroUseImports {
             }
         }
         if !self.mac_refs.is_empty() {
-            println!("{:#?}", self.mac_refs);
+            // TODO if not empty we found one would could not make a suggestion for
+            // such as std::prelude::v1 or something else I haven't thought of.
+            // println!("{:#?}", self.mac_refs);
         }
     }
 }