genirq: Provide irq_desc_has_action

If we have a reference to irq_desc already, there is no point to do
another lookup.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/20150802203609.638130301@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/irqdesc.h

@@ -166,12 +166,16 @@ static inline int handle_domain_irq(struct irq_domain *domain,
 #endif
 
 /* Test to see if a driver has successfully requested an irq */
-static inline int irq_has_action(unsigned int irq)
+static inline int irq_desc_has_action(struct irq_desc *desc)
 {
-	struct irq_desc *desc = irq_to_desc(irq);
 	return desc->action != NULL;
 }
 
+static inline int irq_has_action(unsigned int irq)
+{
+	return irq_desc_has_action(irq_to_desc(irq));
+}
+
 /* caller has locked the irq_desc and both params are valid */
 static inline void __irq_set_handler_locked(unsigned int irq,
 					    irq_flow_handler_t handler)