No need for hook. It gives error as 'ediprolog is not defined.

CHANGELOG.develop

@@ -2369,6 +2369,8 @@ Other:
 - Key bindings:
   - add ~c~ to clear the buffer (thanks to Francesc Elies)
   - bind ~q~ to quit-window in view mode (thanks to Saulius Menkevičius)
+**** Prolog
+- Fixed autoloading error (thanks to jpathy)
 **** Purescript
 - Enabled =purescript-decl-scan-mode= when loading =purescript-mode=
   (thanks to Bjarke Vad Andersen)

layers/+lang/prolog/packages.el

@@ -61,7 +61,6 @@
 
 (defun prolog/init-ediprolog ()
   (use-package ediprolog
-    :hook prolog-mode
     :config
     (progn
       (spacemacs/set-leader-keys-for-major-mode 'prolog-mode