genirq: Update the a comment typo

Change the comment "chasnge" to "change".

Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Link: http://lkml.kernel.org/r/1392020037-5484-2-git-send-email-chuansheng.liu@intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>