Fix printk format warning in block_io.c:

kernel/power/block_io.c:41: warning: format '%ld' expects type 'long int', but argument 2 has type 'sector_t'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>