alloc_per_cpu_data() is called by find_memory(), which is marked as
__init.  Therefore alloc_per_cpu_data() can also be marked as __init to
remedy this modpost problem.

WARNING: modpost: vmlinux.o: section mismatch in reference: alloc_per_cpu_data (section: .text) -> memblock_alloc_try_nid (section: .init.text)

Link: https://lkml.kernel.org/r/20230223034258.12917-1-rdunlap@infradead.org
Fixes: 4b9ddc7c ("[IA64] Fix section mismatch in contig.c version of per_cpu_init()")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>