mm: make alloc_pages_mpol() static

mm: make alloc_pages_mpol() static

All callers outside mempolicy.c now use folio_alloc_mpol() thanks to
Kefeng's cleanups, so we can remove this as a visible symbol.

And also remove the alloc_hooks for alloc_pages_mpol(), since all users
in mempolicy.c are using the nonprof version.

Link: https://lkml.kernel.org/r/20241125210149.2976098-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>