backlight: pwm-backlight: Remove struct backlight_ops.check_fb

The internal check_fb callback from struct pwm_bl_data is never
implemented. The driver's implementation of check_fb always
returns true, which is the backlight core's default if no
implementation has been set. So remove the code from the driver.

v2:
* reword commit message

Signed-off-by: Thomas Zimmermann <[e-mail]>
Cc: Uwe Kleine-König <[e-mail]>
Acked-by: Uwe Kleine-König <[e-mail]>
Reviewed-by: Daniel Thompson <[e-mail]>
Reviewed-by: Javier Martinez Canillas <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/video/backlight/pwm_bl.c

···
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
-#include <linux/fb.h>
 #include <linux/backlight.h>
 #include <linux/err.h>
 #include <linux/pwm.h>
···
 					  int brightness);
 	void			(*notify_after)(struct device *,
 					int brightness);
-	int			(*check_fb)(struct device *, struct fb_info *);
 	void			(*exit)(struct device *);
 };
 
···
 	return 0;
 }
 
-static int pwm_backlight_check_fb(struct backlight_device *bl,
-				  struct fb_info *info)
-{
-	struct pwm_bl_data *pb = bl_get_data(bl);
-
-	return !pb->check_fb || pb->check_fb(pb->dev, info);
-}
-
 static const struct backlight_ops pwm_backlight_ops = {
 	.update_status	= pwm_backlight_update_status,
-	.check_fb	= pwm_backlight_check_fb,
 };
 
 #ifdef CONFIG_OF
···
 
 	pb->notify = data->notify;
 	pb->notify_after = data->notify_after;
-	pb->check_fb = data->check_fb;
 	pb->exit = data->exit;
 	pb->dev = &pdev->dev;
 	pb->enabled = false;

include/linux/pwm_backlight.h

···
 	int (*notify)(struct device *dev, int brightness);
 	void (*notify_after)(struct device *dev, int brightness);
 	void (*exit)(struct device *dev);
-	int (*check_fb)(struct device *dev, struct fb_info *info);
 };
 
 #endif