exfat: fix setting uninitialized time to ctime/atime

An uninitialized time is set to ctime/atime in __exfat_write_inode().
It causes xfstests generic/003 and generic/192 to fail.

And since there will be a time gap between setting ctime/atime to
the inode and writing back the inode, so ctime/atime should not be
set again when writing back the inode.

Fixes: 4c72a36e ("exfat: convert to new timestamp accessors")
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

fs/exfat/inode.c

@@ -56,18 +56,18 @@ int __exfat_write_inode(struct inode *inode, int sync)
 			&ep->dentry.file.create_time,
 			&ep->dentry.file.create_date,
 			&ep->dentry.file.create_time_cs);
+	ts = inode_get_mtime(inode);
 	exfat_set_entry_time(sbi, &ts,
 			     &ep->dentry.file.modify_tz,
 			     &ep->dentry.file.modify_time,
 			     &ep->dentry.file.modify_date,
 			     &ep->dentry.file.modify_time_cs);
-	inode_set_mtime_to_ts(inode, ts);
+	ts = inode_get_atime(inode);
 	exfat_set_entry_time(sbi, &ts,
 			     &ep->dentry.file.access_tz,
 			     &ep->dentry.file.access_time,
 			     &ep->dentry.file.access_date,
 			     NULL);
-	inode_set_atime_to_ts(inode, ts);
 
 	/* File size should be zero if there is no cluster allocated */
 	on_disk_size = i_size_read(inode);