[PATCH] drm/fbdev-generic: fix potential out-of-bounds access

[Sui Jingfeng]

On 2023/4/13 01:13, Sui Jingfeng wrote:
> I finally got reject by drm_fbdev_generic_helper_fb_dirty() with 
> follow code: 


It finally got rejected by drm_fbdev_generic_helper_fb_dirty() function 
with follow code: