zonefs: use ZONEFS_SUPER_SIZE instead of PAGE_SIZE

Use ZONEFS_SUPER_SIZE constant instead of PAGE_SIZE allocating memory for
reading the super block in zonefs_read_super().

While PAGE_SIZE technically isn't incorrect as Linux doesn't support pages
smaller than 4k ZONEFS_SUPER_SIZE is semantically more correct.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

Author: morbidrsa

fs/zonefs/super.c

@@ -1113,11 +1113,12 @@ static int zonefs_read_super(struct super_block *sb)
 	u32 crc, stored_crc;
 	int ret;
 
-	super = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	super = kmalloc(ZONEFS_SUPER_SIZE, GFP_KERNEL);
 	if (!super)
 		return -ENOMEM;
 
-	ret = bdev_rw_virt(sb->s_bdev, 0, super, PAGE_SIZE, REQ_OP_READ);
+	ret = bdev_rw_virt(sb->s_bdev, 0, super, ZONEFS_SUPER_SIZE,
+			   REQ_OP_READ);
 	if (ret)
 		goto free_super;