The omitted parenthesis prevents the addition operation when
acpi_penalize_isa_irq function is called.

Fixes: 103544d8 (ACPI,PCI,IRQ: reduce resource requirements)
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>