Apply `collapsible_if` to Clippy itself

Since Clippy uses the `let_chains` feature, there are many occasions to
collapse `if` and `if let` statements.

1 files changed, 5 insertions, 6 deletions

diff --git a/clippy_lints/src/mutable_debug_assertion.rs b/clippy_lints/src/mutable_debug_assertion.rs
index 3d943bf5b37..d5bed54f0be 100644
--- a/clippy_lints/src/mutable_debug_assertion.rs
+++ b/clippy_lints/src/mutable_debug_assertion.rs
@@ -97,14 +97,13 @@ impl<'tcx> Visitor<'tcx> for MutArgVisitor<'_, 'tcx> {
                 return;
             },
             ExprKind::Path(_) => {
-                if let Some(adj) = self.cx.typeck_results().adjustments().get(expr.hir_id) {
-                    if adj
+                if let Some(adj) = self.cx.typeck_results().adjustments().get(expr.hir_id)
+                    && adj
                         .iter()
                         .any(|a| matches!(a.target.kind(), ty::Ref(_, _, Mutability::Mut)))
-                    {
-                        self.found = true;
-                        return;
-                    }
+                {
+                    self.found = true;
+                    return;
                 }
             },
             // Don't check await desugars