net: hinic: fix incorrect assignment issue in hinic_set_interrupt_cfg()

The value of lli_credit_cnt is incorrectly assigned, fix it.

Fixes: a0337c0d ("hinic: add support to set and get irq coalesce")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>