Silence byte-compiler

Silence byte-compiler

* lisp/ox.el (org-export-backend):
(org-export-define-backend):
(org-export-define-derived-backend):
(org-export--get-subtree-options):
(org-export--get-inbuffer-options):
(org-export--collect-headline-numbering):
(org-export--selected-trees):
(org-export--skip-p):
(org-export--delete-comments):
(org-export--remove-uninterpreted-data-1):
(org-export--merge-external-footnote-definitions):
(org-export-insert-default-template):
(org-export-expand-include-keyword):
(org-export--inclusion-absolute-lines):
(org-export-collect-footnote-definitions):
(org-export-get-footnote-number):
(org-export-get-reference):
(org-export-get-ordinal):
(org-export-unravel-code):
(org-export-format-code):
(org-export-format-code-default):
(org-export-table-has-header-p):
(org-export-table-row-group):
(org-export-table-cell-alignment):
(org-export-table-row-number):
(org-export-table-dimensions):
(org-export-table-cell-address):
(org-export-get-table-cell-at):
(org-export--smart-quote-status):
(org-export-get-previous-element):
(org-export-get-next-element):
(org-export-dispatch):
(org-export--dispatch-ui):
(org-export--dispatch-action): Silence byte-compiler.