x86/PCI: Fix coding style in PIRQ table verification

Remove an extraneous space with a cast in `pirq_check_routing_table'.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2203310017260.44113@angie.orcam.me.uk