btrfs: zoned: initialize device's zone info for seeding

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: initialize device's zone info for seeding When performing seeding on a zoned filesystem it is necessary to initialize each zoned device's btrfs_zoned_device_info structure, otherwise mounting the filesystem will cause a NULL pointer dereference. This was uncovered by fstests' testcase btrfs/163.