x86/irq: Remove useless return value from do_IRQ()

Nothing is using it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.826870369@linutronix.de

arch/x86/include/asm/irq.h

@@ -36,7 +36,7 @@ extern void native_init_IRQ(void);
 
 extern void handle_irq(struct irq_desc *desc, struct pt_regs *regs);
 
-extern __visible unsigned int do_IRQ(struct pt_regs *regs);
+extern __visible void do_IRQ(struct pt_regs *regs);
 
 extern void init_ISA_irqs(void);
 

arch/x86/kernel/irq.c

@@ -230,7 +230,7 @@ u64 arch_irq_stat(void)
  * SMP cross-CPU interrupts have their own specific
  * handlers).
  */
-__visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
+__visible void __irq_entry do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 	struct irq_desc * desc;
@@ -263,7 +263,6 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 	exiting_irq();
 
 	set_irq_regs(old_regs);
-	return 1;
 }
 
 #ifdef CONFIG_X86_LOCAL_APIC