Mark variables set but unused.

Mark variables set but unused.

	* src/lisp.h (PRIVATE_EXTERNAL_LIST_LOOP_6): Mark elt as unused.
	(PRIVATE_EXTERNAL_ALIST_LOOP_8): Set elt_car and elt_cdr as unused.
	* src/mule/mule-ccl.c (CCL_WRITE_STRING): Set bytes as unused.
	* src/ui/X11/dialog-x.c (dbox_descriptor_to_widget_value): Set
	title as unused.
	* src/ui/X11/glyphs-x.c (x_widget_instantiate): Set nm as unused.
	* src/ui/X11/gui-x.c (button_item_to_widget_value): Set intlen as
	unused.
	* src/ui/X11/objects-x.c (x_font_instance_properties): Set
	name_len as unused.
	* src/ui/lwlib/lwlib-Xlw.c (xlw_update_one_widget): Set mw as
	unused.
	* src/ui/lwlib/xlwtabs.c (TabsResize): Set tab as unused.

Signed-off-by: Nelson Ferreira <nelson.ferreira@ieee.org>