quotaio_xfs: Fix error handling in xfs_read_dquot()

When quotactl(2) fails, xfs_read_dquot() will happily return zero-filled
structure. This is fine when the user structure does not exist but it is
wrong when there's other error (like EACCESS). Fix the error handling.

Signed-off-by: Jan Kara <jack@suse.cz>
1 file changed