hinic3: Remove defensive txq_num check

hinic3: Remove defensive txq_num check

Since commit 1f3838b84a63 ("hinic3: Add Rss function") nic_dev->num_txqs
cannot be zero in hinic3_alloc_txqs(). So remove the check for this case.

Link: https://lore.kernel.org/netdev/20250902180843.5ba05bf2@kernel.org/
Co-developed-by: Zhu Yikai <zhuyikai1@h-partners.com>
Signed-off-by: Zhu Yikai <zhuyikai1@h-partners.com>
Signed-off-by: Fan Gong <gongfan1@huawei.com>
Link: https://patch.msgid.link/c23daa9b79fa731c1caaec9b8245f6b2c4994afb.1769656467.git.zhuyikai1@h-partners.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>