arm64: Use reboot_cpu instead of hardconding it to 0

Use `reboot_cpu` variable instead of hardcoding 0 as the reboot cpu in
machine_shutdown().

Signed-off-by: Qais Yousef <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

Author: Qais Yousef

arch/arm64/kernel/process.c

@@ -145,7 +145,7 @@ void arch_cpu_idle_dead(void)
  */
 void machine_shutdown(void)
 {
-	smp_shutdown_nonboot_cpus(0);
+	smp_shutdown_nonboot_cpus(reboot_cpu);
 }
 
 /*