cr_backlight_probe() allocates too little storage for struct cr_panel

The Coverity checker noticed that we allocate too little storage for
"struct cr_panel *crp" in cr_backlight_probe().

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: Thomas Hellstrom <thomas@tungstengraphics.com>
Cc: Alan Hourihane <alanh@tungstengraphics.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>