video: of: display_timing: Add of_node_put() in of_get_display_timing()

From code inspection it can be seen that of_get_display_timing() is
lacking an of_node_put(). Add it.

Fixes: ffa3fd21de8a ("videomode: implement public of_get_display_timing()")
Signed-off-by: Douglas Anderson <[e-mail]>
Reviewed-by: Sam Ravnborg <[e-mail]>
Cc: Thierry Reding <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Philipp Zabel <[e-mail]>
Cc: Tomi Valkeinen <[e-mail]>
Cc: Laurent Pinchart <[e-mail]>
Cc: Russell King <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/video/of_display_timing.c

···
 		struct display_timing *dt)
 {
 	struct device_node *timing_np;
+	int ret;
 
 	if (!np)
 		return -EINVAL;
···
 		return -ENOENT;
 	}
 
-	return of_parse_display_timing(timing_np, dt);
+	ret = of_parse_display_timing(timing_np, dt);
+
+	of_node_put(timing_np);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(of_get_display_timing);