[BUG resend next-20230818] error: 'prepare_elf_headers' defined but not used

[Paul E. McKenney]

Hello!

This morning's rcutorture testing on next-20230818 complained about
prepare_elf_headers() being defined but unused on several rcutorture
scenarios.  The patch below makes rcutorture happy, but might or might
not be a proper fix.

This is a resend adding a few more people on CC, given a possible
relationship to 9f1f399ca999 ("x86/crash: add x86 crash hotplug support").

Thoughts?

							Thanx, Paul

------------------------------------------------------------------------

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 1d0f824559fce..926c39e22387b 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -127,7 +127,8 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
 	crash_save_cpu(regs, safe_smp_processor_id());
 }
 
-#if defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)
+#if (defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)) && defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
+
 static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
 {
 	unsigned int *nr_ranges = arg;