ocfs2_direct_IO_write() misses ocfs2_is_overwrite() error code

If ocfs2_is_overwrite failed, ocfs2_direct_IO_write mays till return
success to the caller.
Signed-off-by: Norton.Zhu <norton.zhu@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/aops.c

@@ -864,6 +864,7 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
 		is_overwrite = ocfs2_is_overwrite(osb, inode, offset);
 		if (is_overwrite < 0) {
 			mlog_errno(is_overwrite);
+			ret = is_overwrite;
 			ocfs2_inode_unlock(inode, 1);
 			goto clean_orphan;
 		}