net/mlx4_core: Adjust allocation type for buddy->bits

net/mlx4_core: Adjust allocation type for buddy->bits

In preparation for making the kmalloc family of allocators type aware,
we need to make sure that the returned type from the allocation matches
the type of the variable being assigned. (Before, the allocator would
always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "unsigned long **", but the returned type will be
"long **". These are the same size allocation (pointer size) but the
types do not match. Adjust the allocation type to match the assignment.

Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250426060757.work.865-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>