mm: fix obsolete function name above debug_pagealloc_enabled_static()

Since commit 04013513 ("mm, page_alloc: do not rely on the order of
page_poison and init_on_alloc/free parameters"), init_debug_pagealloc() is
converted to init_mem_debugging_and_hardening().  Later it's renamed to
mem_debugging_and_hardening_init() via commit f2fc4b44

 ("mm: move
init_mem_debugging_and_hardening() to mm/mm_init.c").

Link: https://lkml.kernel.org/r/20230720112806.3851893-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>