console: remove unreachable code

In the current code, line 497 checks if `item` is `null` or `undefined`.
However, `item` is guaranteed to be a non-null object or function at
that point.

* Lines 484/485 set `primitive` to `true` if `item` is null or
  undefined.
* Line 486 skips line 497 if `primitive` is true (which it will always
  be if `item` is null or undefined) and `properties` is undefined. So
  the only way to get to line 497 when `item` is null or undefined is if
  `properties` is specified.
* Line 494 skips line 497 if `primitive` is true (which it will always
  be if `item` is null or undefined) and `properties` are specified
  (which will always be the case or else this `else` block is skipped.)

Here are the current lines 484 through 497:

      const primitive = item === null ||
          (typeof item !== 'function' && typeof item !== 'object');
      if (properties === undefined && primitive) {
        hasPrimitives = true;
        valuesKeyArray[i] = _inspect(item);
      } else {
        const keys = properties || ObjectKeys(item);
        for (const key of keys) {
          if (map[key] === undefined)
            map[key] = [];
          if ((primitive && properties) || !hasOwnProperty(item, key))
            map[key][i] = '';
          else
            map[key][i] = item == null ? item : _inspect(item[key]);

This change removes the unnecessary ternary in that final line,
simplifying it to:

            map[key][i] = _inspect(item[key]);

PR-URL: nodejs#26906
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>

lib/internal/console/constructor.js

@@ -494,7 +494,7 @@ const consoleMethods = {
           if ((primitive && properties) || !hasOwnProperty(item, key))
             map[key][i] = '';
           else
-            map[key][i] = item == null ? item : _inspect(item[key]);
+            map[key][i] = _inspect(item[key]);
         }
       }
     }