Simplify loop and remove old debugging code

Co-authored-by: Joshua Nelson <jyn514@gmail.com>

src/librustdoc/clean/utils.rs

@@ -636,21 +636,12 @@ fn print_const_with_custom_print_scalar(cx: &DocContext<'_>, ct: &'tcx ty::Const
         let mut current = def_id;
         // The immediate parent might not always be a module.
         // Find the first parent which is.
-        loop {
-            if let Some(parent) = tcx.parent(current) {
-                if tcx.def_kind(parent) == DefKind::Mod {
-                    break Some(parent);
-                }
-                current = parent;
-            } else {
-                debug!(
-                    "{:?} has no parent (kind={:?}, original was {:?})",
-                    current,
-                    tcx.def_kind(current),
-                    def_id
-                );
-                break None;
+        while let Some(parent) = tcx.parent(current) {
+            if tcx.def_kind(parent) == DefKind::Mod {
+                return Some(parent);
             }
+            current = parent;
         }
+        None
     }
 }