[PATCH] fbmem: use unregister_chrdev() on unload

fbdev is missing unregister_chrdev() on unload.

Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>