genirq: Use the proper parameter name in kernel doc

The following warning is emitted for make xmldocs:

 Warning(.//kernel/irq/chip.c:1009): No description found for parameter 'vcpu_info'
 Warning(.//kernel/irq/chip.c:1009): Excess function parameter 'dest' description in 'irq_chip_set_vcpu_affinity_parent'
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Link: http://lkml.kernel.org/r/1438164576-5945-1-git-send-email-standby24x7@gmail.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/irq/chip.c

@@ -1003,7 +1003,7 @@ int irq_chip_retrigger_hierarchy(struct irq_data *data)
 /**
  * irq_chip_set_vcpu_affinity_parent - Set vcpu affinity on the parent interrupt
  * @data:	Pointer to interrupt specific data
- * @dest:	The vcpu affinity information
+ * @vcpu_info:	The vcpu affinity information
  */
 int irq_chip_set_vcpu_affinity_parent(struct irq_data *data, void *vcpu_info)
 {