scsi: scsi_debug: Use vcalloc() to simplify code

Use vcalloc() instead of vmalloc() followed by bitmap_zero() to simplify
the function sdebug_add_store().

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Link: https://lore.kernel.org/r/20250806124633.383426-3-rongqianfeng@vivo.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: qianfengrong

drivers/scsi/scsi_debug.c

@@ -8782,8 +8782,8 @@ static int sdebug_add_store(void)
 	/* Logical Block Provisioning */
 	if (scsi_debug_lbp()) {
 		map_size = lba_to_map_index(sdebug_store_sectors - 1) + 1;
-		sip->map_storep = vmalloc(array_size(sizeof(long),
-						     BITS_TO_LONGS(map_size)));
+		sip->map_storep = vcalloc(BITS_TO_LONGS(map_size),
+					  sizeof(long));
 
 		pr_info("%lu provisioning blocks\n", map_size);
 
@@ -8792,8 +8792,6 @@ static int sdebug_add_store(void)
 			goto err;
 		}
 
-		bitmap_zero(sip->map_storep, map_size);
-
 		/* Map first 1KB for partition table */
 		if (sdebug_num_parts)
 			map_region(sip, 0, 2);