linux/irq.h: fix kernel-doc warning

From: Randy Dunlap <[email protected]>

Fix kernel-doc warning. This struct member was removed in commit id 875682648b89a3ebc06176d60dc280f810647839:

	irq: Remove irq_chip->release()

so remove its associated kernel-doc entry also.

Warning(include/linux/irq.h:338): Excess struct/union/enum/typedef member 'release' description in 'irq_chip'

---
 include/linux/irq.h |    2 --
 1 file changed, 2 deletions(-)

@@ -301,8 +301,6 @@ static inline irq_hw_number_t irqd_to_hw
  * @irq_pm_shutdown:	function called from core code on shutdown once per chip
  * @irq_print_chip:	optional to print special chip info in show_interrupts
  * @flags:		chip specific flags
- *
- * @release:		release function solely used by UML
  */
 struct irq_chip {
 	const char	*name;