eth: intel: use vmalloc_array() to simplify code

eth: intel: use vmalloc_array() to simplify code

Remove array_size() calls and replace vmalloc() with vmalloc_array() to
simplify the code and maintain consistency with existing kmalloc_array()
usage.

vmalloc_array() is also optimized better, resulting in less instructions
being used.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Link: https://patch.msgid.link/20250816090659.117699-2-rongqianfeng@vivo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>