org-agenda.el: Fix one byte-compiler warning

lisp/org-agenda.el

@@ -3005,6 +3005,8 @@ This ensures the export commands can easily use it."
 	       (kill-buffer bufname)))))))
 (def-edebug-spec org-batch-store-agenda-views (&rest sexp))
 
+(defvar org-agenda-current-span nil
+  "The current span used in the agenda view.") ; local variable in the agenda buffer
 (defun org-agenda-mark-header-line (pos)
   "Mark the line at POS as an agenda structure header."
   (save-excursion
@@ -3818,8 +3820,6 @@ When EMPTY is non-nil, also include days without any entries."
   "Start day for the agenda view.
 Custom commands can set this variable in the options section.")
 (defvar org-starting-day nil) ; local variable in the agenda buffer
-(defvar org-agenda-current-span nil
-  "The current span used in the agenda view.") ; local variable in the agenda buffer
 (defvar org-arg-loc nil) ; local variable
 
 (defvar org-agenda-entry-types '(:deadline :scheduled :timestamp :sexp)