Add allow unused

Author: Gh0stm4chine

tests/ui/neg_multiply.fixed

@@ -1,6 +1,7 @@
 // run-rustfix
 #![warn(clippy::neg_multiply)]
 #![allow(clippy::no_effect, clippy::unnecessary_operation, clippy::precedence)]
+#![allow(unused)]
 
 use std::ops::Mul;
 

tests/ui/neg_multiply.rs

@@ -1,6 +1,7 @@
 // run-rustfix
 #![warn(clippy::neg_multiply)]
 #![allow(clippy::no_effect, clippy::unnecessary_operation, clippy::precedence)]
+#![allow(unused)]
 
 use std::ops::Mul;
 

tests/ui/neg_multiply.stderr

@@ -1,37 +1,37 @@
 error: this multiplication by -1 can be written more succinctly
-  --> $DIR/neg_multiply.rs:28:5
+  --> $DIR/neg_multiply.rs:29:5
    |
 LL |     x * -1;
    |     ^^^^^^ help: consider using: `-x`
    |
    = note: `-D clippy::neg-multiply` implied by `-D warnings`
 
 error: this multiplication by -1 can be written more succinctly
-  --> $DIR/neg_multiply.rs:30:5
+  --> $DIR/neg_multiply.rs:31:5
    |
 LL |     -1 * x;
    |     ^^^^^^ help: consider using: `-x`
 
 error: this multiplication by -1 can be written more succinctly
-  --> $DIR/neg_multiply.rs:32:11
+  --> $DIR/neg_multiply.rs:33:11
    |
 LL |     100 + x * -1;
    |           ^^^^^^ help: consider using: `-x`
 
 error: this multiplication by -1 can be written more succinctly
-  --> $DIR/neg_multiply.rs:34:5
+  --> $DIR/neg_multiply.rs:35:5
    |
 LL |     (100 + x) * -1;
    |     ^^^^^^^^^^^^^^ help: consider using: `-(100 + x)`
 
 error: this multiplication by -1 can be written more succinctly
-  --> $DIR/neg_multiply.rs:36:5
+  --> $DIR/neg_multiply.rs:37:5
    |
 LL |     -1 * 17;
    |     ^^^^^^^ help: consider using: `-17`
 
 error: this multiplication by -1 can be written more succinctly
-  --> $DIR/neg_multiply.rs:38:14
+  --> $DIR/neg_multiply.rs:39:14
    |
 LL |     0xcafe | 0xff00 * -1;
    |              ^^^^^^^^^^^ help: consider using: `-0xff00`