irq: Remove unused debug_poll_all_shared_irqs()

commit 74296a8ed added this function for debug purposes, but it was
never used for anything. Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 114e704..8996b98 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -104,7 +104,7 @@
 	return ok;
 }
 
-static void poll_all_shared_irqs(void)
+static void poll_spurious_irqs(unsigned long dummy)
 {
 	struct irq_desc *desc;
 	int i;
@@ -123,23 +123,11 @@
 
 		try_one_irq(i, desc);
 	}
-}
-
-static void poll_spurious_irqs(unsigned long dummy)
-{
-	poll_all_shared_irqs();
 
 	mod_timer(&poll_spurious_irq_timer,
 		  jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
 }
 
-#ifdef CONFIG_DEBUG_SHIRQ
-void debug_poll_all_shared_irqs(void)
-{
-	poll_all_shared_irqs();
-}
-#endif
-
 /*
  * If 99,900 of the previous 100,000 interrupts have not been handled
  * then assume that the IRQ is stuck in some manner. Drop a diagnostic