improve wording of a suggestion

compiler/rustc_typeck/src/check/pat.rs

@@ -697,7 +697,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
  Some((
  pat.span,
- format!("to declare a mutable {ident_kind} use `mut variable_name`"),
+ format!("to declare a mutable {ident_kind} use"),
  format!("mut {binding}"),
  ))
 

src/test/ui/mismatched_types/ref-pat-suggestions.stderr

@@ -24,7 +24,7 @@ LL | fn _f1(&mut _a: u32) {}
  |
  = note: expected type `u32`
  found mutable reference `&mut _`
-note: to declare a mutable parameter use `mut variable_name`: `mut _a`
+note: to declare a mutable parameter use: `mut _a`
  --> $DIR/ref-pat-suggestions.rs:4:8
  |
 LL | fn _f1(&mut _a: u32) {}
@@ -127,7 +127,7 @@ LL | let _: fn(u32) = |&mut _a| ();
  |
  = note: expected type `u32`
  found mutable reference `&mut _`
-note: to declare a mutable parameter use `mut variable_name`: `mut _a`
+note: to declare a mutable parameter use: `mut _a`
  --> $DIR/ref-pat-suggestions.rs:12:23
  |
 LL | let _: fn(u32) = |&mut _a| ();
@@ -232,7 +232,7 @@ LL | let _ = |&mut _a: u32| ();
  |
  = note: expected type `u32`
  found mutable reference `&mut _`
-note: to declare a mutable parameter use `mut variable_name`: `mut _a`
+note: to declare a mutable parameter use: `mut _a`
  --> $DIR/ref-pat-suggestions.rs:19:14
  |
 LL | let _ = |&mut _a: u32| ();
@@ -314,7 +314,7 @@ LL | let &mut _a = 0;
  | ^^^^^^^ - this expression has type `{integer}`
  | |
  | expected integer, found `&mut _`
- | help: to declare a mutable variable use `mut variable_name`: `mut _a`
+ | help: to declare a mutable variable use: `mut _a`
  |
  = note: expected type `{integer}`
  found mutable reference `&mut _`
@@ -329,7 +329,7 @@ LL | let S(&mut _b) = S(0);
  |
  = note: expected type `u8`
  found mutable reference `&mut _`
-note: to declare a mutable binding use `mut variable_name`: `mut _b`
+note: to declare a mutable binding use: `mut _b`
  --> $DIR/ref-pat-suggestions.rs:30:15
  |
 LL | let S(&mut _b) = S(0);
@@ -350,7 +350,7 @@ LL | let (&mut _c,) = (0,);
  |
  = note: expected type `{integer}`
  found mutable reference `&mut _`
-note: to declare a mutable binding use `mut variable_name`: `mut _c`
+note: to declare a mutable binding use: `mut _c`
  --> $DIR/ref-pat-suggestions.rs:31:14
  |
 LL | let (&mut _c,) = (0,);
@@ -371,7 +371,7 @@ LL | &mut _d => {}
  |
  = note: expected type `{integer}`
  found mutable reference `&mut _`
-note: to declare a mutable binding use `mut variable_name`: `mut _d`
+note: to declare a mutable binding use: `mut _d`
  --> $DIR/ref-pat-suggestions.rs:34:13
  |
 LL | &mut _d => {}

src/test/ui/pattern/for-loop-bad-item.stderr

@@ -8,7 +8,7 @@ LL | for ((_, _), (&mut c, _)) in &mut map {
  |
  = note: expected type `char`
  found mutable reference `&mut _`
-note: to declare a mutable binding use `mut variable_name`: `mut c`
+note: to declare a mutable binding use: `mut c`
  --> $DIR/for-loop-bad-item.rs:7:19
  |
 LL | for ((_, _), (&mut c, _)) in &mut map {