Revert last change to ivy-update-candidates

This reverts commit 71c59ae
"ivy.el (ivy--format-minibuffer-line): Check for annotation-function
in one more place".

It seems to have broken downstream packages, so I'm reverting it for
now, until Oleh Krehel or some other more experienced person can
revisit it in earnest.

Re: #2783.

ivy.el

@@ -3284,14 +3284,10 @@ The function was added in Emacs 26.1.")
           "~"
         home)))))
 
-(defvar ivy--minibuffer-metadata nil)
-
 (defun ivy-update-candidates (cands)
-  (let ((ivy--minibuffer-metadata
-         (completion-metadata "" minibuffer-completion-table minibuffer-completion-predicate)))
-    (ivy--insert-minibuffer
-     (ivy--format
-      (setq ivy--all-candidates cands)))))
+  (ivy--insert-minibuffer
+   (ivy--format
+    (setq ivy--all-candidates cands))))
 
 (defun ivy--exhibit ()
   "Insert Ivy completions display.
@@ -4034,8 +4030,7 @@ in this case."
                     (funcall ivy--highlight-function str))
                 str))
          (olen (length str))
-         (annot (or (completion-metadata-get ivy--minibuffer-metadata 'annotation-function)
-                    (plist-get completion-extra-properties :annotation-function))))
+         (annot (plist-get completion-extra-properties :annotation-function)))
     (add-text-properties
      0 olen
      '(mouse-face