Fix 'exchange-point-and-mark' in 'transient-mark-mode'

* lisp/simple.el (exchange-point-and-mark): Don't deactivate mark
when 'transient-mark-mode' is ON.  (Bug#53150)

(cherry picked from commit 415ed4b425)

lisp/simple.el

@@ -6652,11 +6652,10 @@ mode temporarily."
         (user-error "No mark set in this buffer"))
     (set-mark (point))
     (goto-char omark)
-    (cond ((and (not arg) (not temp-highlight))
-	   (setq-local transient-mark-mode (cons 'only transient-mark-mode)))
-	  ((xor arg (not (region-active-p)))
-	   (deactivate-mark))
-	  (t (activate-mark)))
+    (or temp-highlight
+        (cond ((xor arg (not (region-active-p)))
+	       (deactivate-mark))
+	      (t (activate-mark))))
     nil))
 
 (defcustom shift-select-mode t