drivers/block/z2ram.c: correct printing of sector_t

If CONFIG_LBDAF=y, `sector_t' becomes `u64' instead of `unsigned long':

drivers/block/z2ram.c: In function ¡do_z2_request¢:
drivers/block/z2ram.c:83: warning: format %lu expects type `long unsigned int', but argument 2 has type `sector_t'

Hence always cast it to `unsigned long long' for printing.  Also do the
pr_err() dance, while we're at it.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>