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 <[e-mail]>
Cc: Jiang Liu <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Rusty Russell <[e-mail]>
Cc: Bjorn Helgaas <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Thomas Gleixner <[e-mail]>

include/linux/irqdesc.h

···
 #endif
 
 /* Test to see if a driver has successfully requested an irq */
+static inline int irq_desc_has_action(struct irq_desc *desc)
+{
+	return desc->action != NULL;
+}
+
 static inline int irq_has_action(unsigned int irq)
 {
-	struct irq_desc *desc = irq_to_desc(irq);
-	return desc->action != NULL;
+	return irq_desc_has_action(irq_to_desc(irq));
 }
 
 /* caller has locked the irq_desc and both params are valid */