proper __do_softirq() prototype

Add a proper prototype for __do_softirq() in include/linux/interrupt.h

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/s390/kernel/irq.c

@@ -60,8 +60,6 @@ init_IRQ(void)
 /*
  * Switch to the asynchronous interrupt stack for softirq execution.
  */
-extern void __do_softirq(void);
-
 asmlinkage void do_softirq(void)
 {
 	unsigned long flags, old, new;

arch/sh/kernel/irq.c

@@ -200,8 +200,6 @@ void irq_ctx_exit(int cpu)
 	hardirq_ctx[cpu] = NULL;
 }
 
-extern asmlinkage void __do_softirq(void);
-
 asmlinkage void do_softirq(void)
 {
 	unsigned long flags;

arch/x86/kernel/irq_32.c

@@ -190,8 +190,6 @@ void irq_ctx_exit(int cpu)
 	hardirq_ctx[cpu] = NULL;
 }
 
-extern asmlinkage void __do_softirq(void);
-
 asmlinkage void do_softirq(void)
 {
 	unsigned long flags;

include/asm-powerpc/irq.h

@@ -619,8 +619,6 @@ struct pt_regs;
 
 #define __ARCH_HAS_DO_SOFTIRQ
 
-extern void __do_softirq(void);
-
 #ifdef CONFIG_IRQSTACKS
 /*
  * Per-cpu stacks for handling hard and soft interrupts.

include/linux/interrupt.h

@@ -289,6 +289,7 @@ struct softirq_action
 };
 
 asmlinkage void do_softirq(void);
+asmlinkage void __do_softirq(void);
 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 extern void softirq_init(void);
 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)