fbdev: Rework fb_blank()

Reimplement fb_blank() to return early on errors. No functional
changes. Prepares the helper for tracking the blanking state in
struct fb_info.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20250321095517.313713-2-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>

Author: Thomas Zimmermann

drivers/video/fbdev/core/fbmem.c

@@ -339,25 +339,27 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 }
 EXPORT_SYMBOL(fb_set_var);
 
-int
-fb_blank(struct fb_info *info, int blank)
+int fb_blank(struct fb_info *info, int blank)
 {
 	struct fb_event event;
-	int ret = -EINVAL;
+	int ret;
+
+	if (!info->fbops->fb_blank)
+		return -EINVAL;
 
 	if (blank > FB_BLANK_POWERDOWN)
 		blank = FB_BLANK_POWERDOWN;
 
 	event.info = info;
 	event.data = ␣
 
-	if (info->fbops->fb_blank)
-		ret = info->fbops->fb_blank(blank, info);
+	ret = info->fbops->fb_blank(blank, info);
+	if (ret)
+		return ret;
 
-	if (!ret)
-		fb_notifier_call_chain(FB_EVENT_BLANK, &event);
+	fb_notifier_call_chain(FB_EVENT_BLANK, &event);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(fb_blank);