Staging: ft1000-usb: use the correct list head

Using pdpram_blk here would cause an oops.  We intended to use
&freercvpool.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Tested by: Marek Belisko <marek.belisko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>