Ensure that the i_flags field of struct zonefs_inode_info is cleared to
0 when initializing a zone file inode, avoiding seeing the flag
ZONEFS_ZONE_OPEN being incorrectly set.

Fixes: b5c00e97 ("zonefs: open/close zone on file open/close")
Cc: <stable@vger.kernel.org>
Signed-off-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NHans Holmberg <hans.holmberg@wdc.com>