resolve clippy errors

Signed-off-by: onur-ozkan <work@onurozkan.dev>

compiler/rustc_const_eval/src/interpret/intern.rs

@@ -291,7 +291,9 @@ pub fn intern_const_alloc_for_constprop<
         return Ok(());
     }
     // Move allocation to `tcx`.
-    for _ in intern_shallow(ecx, alloc_id, Mutability::Not).map_err(|()| err_ub!(DeadLocal))? {
+    if let Some(_) =
+        (intern_shallow(ecx, alloc_id, Mutability::Not).map_err(|()| err_ub!(DeadLocal))?).next()
+    {
         // We are not doing recursive interning, so we don't currently support provenance.
         // (If this assertion ever triggers, we should just implement a
         // proper recursive interning loop -- or just call `intern_const_alloc_recursive`.