ipvlan: limit loop_qlen ranges

euler inclusion
category: bugfix
bugzilla: 4411
CVE: NA

-------------------------------------------------

In order to avoid integer overflow, we should limit
the ranges of loop_qlen value.

Fixes: 997518dea253 ("ipvlan: Introduce local xmit queue for l2e mode")
Signed-off-by: Keefe Liu <liuqifa@huawei.com>
Reviewed-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>