drm/fb-helper: improve DRM fbdev emulation device names

Framebuffer devices that are registered by DRM drivers for fbdev emulation
have a "drmfb" suffix in their name. But makes them to be quite confusing
for drivers that already have "drm" in their name:

$ cat /proc/fb
0 rockchipdrmdrmfb

$ cat /proc/fb
0 simpledrmdrmfb

Also, there isn't a lot of value in adding these "drmfb" suffices to their
names, since users shouldn't really care if the FB devices were registered
by a real fbdev driver or a DRM driver using the fbdev emulation.

What programs should be interested about is if there's a DRM device, and
there are better ways to query that info than reading this procfs entry.

So let's just remove the suffix, which leads to much better device names:

$ cat /proc/fb
0 rockchipdrm

$ cat /proc/fb
0 simpledrm
Suggested-by: NThomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210525151313.3379622-1-javierm@redhat.com

drivers/gpu/drm/drm_fb_helper.c

@@ -1737,7 +1737,7 @@ void drm_fb_helper_fill_info(struct fb_info *info,
 			       sizes->fb_width, sizes->fb_height);
 
 	info->par = fb_helper;
-	snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
+	snprintf(info->fix.id, sizeof(info->fix.id), "%s",
 		 fb_helper->dev->driver->name);
 
 }