Make it auto fixable lint

Author: JohnTitor

clippy_lints/src/misc_early.rs

@@ -312,14 +312,17 @@ impl EarlyLintPass for MiscEarlyLints {
 
         if let PatKind::Ident(_, ident, Some(ref right)) = pat.node {
             if let PatKind::Wild = right.node {
-                span_lint(
+                span_lint_and_sugg(
                     cx,
                     REDUNDANT_PATTERN,
                     pat.span,
                     &format!(
                         "the `{} @ _` pattern can be written as just `{}`",
                         ident.name, ident.name,
                     ),
+                    "try",
+                    format!("{}", ident.name),
+                    Applicability::MachineApplicable,
                 );
             }
         }

tests/ui/patterns.stderr

@@ -2,7 +2,7 @@ error: the `y @ _` pattern can be written as just `y`
   --> $DIR/patterns.rs:10:9
    |
 LL |         y @ _ => (),
-   |         ^^^^^
+   |         ^^^^^ help: try: `y`
    |
    = note: `-D clippy::redundant-pattern` implied by `-D warnings`