[PATCH] x86/irq: Fix -Wmissing-prototypes warning for init_IRQ()

[Yi Wang]

We get a warning when building kernel with W=1:
arch/x86/kernel/irqinit.c:79:13: warning: no previous prototype for âinit_IRQâ [-Wmissing-prototypes]
 void __init init_IRQ(void)
             ^

Add the missing declaration in head file to fix this.

Signed-off-by: Yi Wang <wang.yi59@xxxxxxxxxx>
---
 arch/x86/include/asm/irq.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 2395bb7..399a9c5 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -41,6 +41,8 @@ static inline int irq_canonicalize(int irq)
 
 extern void init_ISA_irqs(void);
 
+extern void __init init_IRQ(void);
+
 #ifdef CONFIG_X86_LOCAL_APIC
 void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
 				    bool exclude_self);
-- 
1.8.3.1