Fix the pool size alignment issue

[PointKernel]

Description

This PR fixes a pool size alignment bug.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[PointKernel]

Depending on how reviewers see this,

cudf/cpp/src/utilities/pinned_memory.cpp

Line 46 in 3cb3df3

: pool_size_{size}, pool_{new host_pooled_mr(upstream_mr_, size, size)}

Is the fixed_pinned_pool_memory_resource ctor is a better place to do this round up calculation?

[bdice]

Is the fixed_pinned_pool_memory_resource ctor is a better place to do this round up calculation?

Yes, I think so. It guarantees a higher degree of safety because make_default_pinned_mr will go through that constructor.

[PointKernel]

/merge