drm/hisilicon/hibmc: fix irq_request()'s irq name variable is local

drm/hisilicon/hibmc: fix irq_request()'s irq name variable is local

The local variable is passed in request_irq (), and there will be use
after free problem, which will make request_irq failed. Using the global
irq name instead of it to fix.

Fixes: b11bc1ae4658 ("drm/hisilicon/hibmc: Add MSI irq getting and requesting for HPD")
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250813094238.3722345-4-shiyongbang@huawei.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>