org-e-latex: Fix coderef display for links with no contents

* contrib/lisp/org-e-latex.el (org-e-latex-link): Fix coderef display
  for links with no contents.
* contrib/lisp/org-e-odt.el (org-e-odt-link): Remove useless test.
* contrib/lisp/org-e-html.el (org-e-html-link): Remove useless test.

contrib/lisp/org-e-html.el

@@ -2485,7 +2485,7 @@ INFO is a plist holding contextual information.  See
 				" onmouseover=\"CodeHighlightOn(this, '%s');\""
 				" onmouseout=\"CodeHighlightOff(this, '%s');\"")
 			fragment fragment)
-		(format (org-export-get-coderef-format path (or desc "%s"))
+		(format (org-export-get-coderef-format path desc)
 			(org-export-resolve-coderef path info)))))
      ;; Link type is handled by a special function.
      ((functionp (setq protocol (nth 2 (assoc type org-link-protocols))))

contrib/lisp/org-e-latex.el

@@ -1512,7 +1512,7 @@ INFO is a plist holding contextual information.  See
      ;; Coderef: replace link with the reference name or the
      ;; equivalent line number.
      ((string= type "coderef")
-      (format (org-export-get-coderef-format path (or desc ""))
+      (format (org-export-get-coderef-format path desc)
 	      (org-export-resolve-coderef path info)))
      ;; Link type is handled by a special function.
      ((functionp (setq protocol (nth 2 (assoc type org-link-protocols))))

contrib/lisp/org-e-odt.el

@@ -3637,7 +3637,7 @@ INFO is a plist holding contextual information.  See
      ;; Coderef: replace link with the reference name or the
      ;; equivalent line number.
      ((string= type "coderef")
-      (let* ((fmt (org-export-get-coderef-format path (or desc "%s")))
+      (let* ((fmt (org-export-get-coderef-format path desc))
 	     (res (org-export-resolve-coderef path info))
 	     (org-e-odt-suppress-xref nil)
 	     (href (org-xml-format-href (concat "#coderef-" path))))