remove redundant var rebindings

compiler/rustc_passes/src/layout_test.rs

@@ -27,7 +27,6 @@ pub fn test_layout(tcx: TyCtxt<'_>) {
 }
 
 fn dump_layout_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribute) {
-    let tcx = tcx;
     let param_env = tcx.param_env(item_def_id);
     let ty = tcx.type_of(item_def_id).instantiate_identity();
     match tcx.layout_of(param_env.and(ty)) {

compiler/rustc_passes/src/liveness.rs

@@ -1105,7 +1105,6 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                 }
 
                 // Then do a second pass for inputs
-                let mut succ = succ;
                 for (op, _op_sp) in asm.operands.iter().rev() {
                     match op {
                         hir::InlineAsmOperand::In { expr, .. } => {