ext4: correct max_inline_xattr_value_size computing

If the ext4 inode does not have xattr space, 0 is returned in the
get_max_inline_xattr_value_size function. Otherwise, the function returns
a negative value when the inode does not contain EXT4_STATE_XATTR.

Cc: stable@kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220616021358.2504451-4-libaokun1@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/inline.c

@@ -36,6 +36,9 @@ static int get_max_inline_xattr_value_size(struct inode *inode,
 	struct ext4_inode *raw_inode;
 	int free, min_offs;
 
+	if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
+		return 0;
+
 	min_offs = EXT4_SB(inode->i_sb)->s_inode_size -
 			EXT4_GOOD_OLD_INODE_SIZE -
 			EXT4_I(inode)->i_extra_isize -