Remove pointless use of intern

* lisp/mwheel.el (mouse-wheel-left-event)
(mouse-wheel-right-event): Replace use of intern with quoted
symbol.
* lisp/profiler.el (profiler-calltree-build-unified): Likewise.
* lisp/vc/ediff-util.el (ediff-debug-info): Likewise.

lisp/mwheel.el

@@ -203,13 +203,13 @@ Also see `mouse-wheel-tilt-scroll'."
 (defvar mouse-wheel-left-event
   (if (or (featurep 'w32-win) (featurep 'ns-win))
       'wheel-left
-    (intern "mouse-6"))
+    'mouse-6)
   "Event used for scrolling left.")
 
 (defvar mouse-wheel-right-event
   (if (or (featurep 'w32-win) (featurep 'ns-win))
       'wheel-right
-    (intern "mouse-7"))
+    'mouse-7)
   "Event used for scrolling right.")
 
 (defun mouse-wheel--get-scroll-window (event)

lisp/profiler.el

@@ -305,7 +305,7 @@ Optional argument MODE means only check for the specified mode (cpu or mem)."
   (let ((fun-map (make-hash-table :test 'profiler-function-equal))
         (parent-map (make-hash-table :test 'eq))
         (leftover-tree (profiler-make-calltree
-                        :entry (intern "...") :parent tree)))
+                        :entry '... :parent tree)))
     (push leftover-tree (profiler-calltree-children tree))
     (maphash
      (lambda (backtrace _count)

lisp/vc/ediff-util.el

@@ -4129,10 +4129,10 @@ Mail anyway? (y or n) ")
     (ediff-with-current-buffer standard-output
       (fundamental-mode))
     (princ (format "\nCtl buffer: %S\n" ediff-control-buffer))
-    (ediff-print-diff-vector (intern "ediff-difference-vector-A"))
-    (ediff-print-diff-vector (intern "ediff-difference-vector-B"))
-    (ediff-print-diff-vector (intern "ediff-difference-vector-C"))
-    (ediff-print-diff-vector (intern "ediff-difference-vector-Ancestor"))
+    (ediff-print-diff-vector 'ediff-difference-vector-A)
+    (ediff-print-diff-vector 'ediff-difference-vector-B)
+    (ediff-print-diff-vector 'ediff-difference-vector-C)
+    (ediff-print-diff-vector 'ediff-difference-vector-Ancestor)
     ))