kernel/fork.c: put set_max_threads()/task_struct_whitelist() in __init section

The functions set_max_threads() and task_struct_whitelist() are only used
by fork_init() during bootup.

Let's add __init tag to them.

Link: https://lkml.kernel.org/r/20240701013410.17260-2-richard.weiyang@gmail.comSigned-off-by: Wei Yang <richard.weiyang@gmail.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kernel/fork.c

@@ -997,7 +997,7 @@ void __init __weak arch_task_cache_init(void) { }
 /*
  * set_max_threads
  */
-static void set_max_threads(unsigned int max_threads_suggested)
+static void __init set_max_threads(unsigned int max_threads_suggested)
 {
 	u64 threads;
 	unsigned long nr_pages = PHYS_PFN(memblock_phys_mem_size() - memblock_reserved_size());
@@ -1023,7 +1023,7 @@ static void set_max_threads(unsigned int max_threads_suggested)
 int arch_task_struct_size __read_mostly;
 #endif
 
-static void task_struct_whitelist(unsigned long *offset, unsigned long *size)
+static void __init task_struct_whitelist(unsigned long *offset, unsigned long *size)
 {
 	/* Fetch thread_struct whitelist for the architecture. */
 	arch_thread_struct_whitelist(offset, size);