Fix "return is not a function, parentheses are not required" checkpatch
error.

Signed-off-by: Ran Sun <sunran001@208suo.com>
---
  arch/x86/kernel/acpi/boot.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 457f1f6622d0..31c0cb4b16e2 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -860,7 +860,7 @@ int acpi_unmap_cpu(int cpu)
  	set_cpu_present(cpu, false);
  	num_processors--;

-	return (0);
+	return 0;
  }
  EXPORT_SYMBOL(acpi_unmap_cpu);
  #endif				/* CONFIG_ACPI_HOTPLUG_CPU */