scsi: sd: sd_zbc: Don't pass GFP_NOIO to kvcalloc

Dan reported we're passing in GFP_NOIO to kvmalloc() which will then
fallback to doing kmalloc() instead of an optional vmalloc() if the size
exceeds kmalloc()s limits. This will break with drives that have zone
numbers exceeding PAGE_SIZE/sizeof(u32).

Instead of passing in GFP_NOIO, enter an implicit GFP_NOIO allocation
scope.

Link: https://lore.kernel.org/r/YCuvSfKw4qEQBr/t@mwanda
Link: https://lore.kernel.org/r/5a6345e2989fd06c049ac4e4627f6acb492c15b8.1613569821.git.johannes.thumshirn@wdc.com


Fixes: 5795eb44: ("scsi: sd_zbc: emulate ZONE_APPEND commands")
Cc: Damien Le Moal <Damien.LeMoal@wdc.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>