zonefs: Clear inode information flags on inode creation

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: b5c00e9 ("zonefs: open/close zone on file open/close")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>

Author: Damien Le Moal

fs/zonefs/super.c

@@ -1142,6 +1142,7 @@ static struct inode *zonefs_alloc_inode(struct super_block *sb)
 	inode_init_once(&zi->i_vnode);
 	mutex_init(&zi->i_truncate_mutex);
 	zi->i_wr_refcnt = 0;
+	zi->i_flags = 0;
 
 	return &zi->i_vnode;
 }