Stop touching irq_desc[irq] directly, instead use accessor
functions provided. Use irq_has_action instead of directly
testing the irq_desc.
Tested-by: NMichael Cree <mcree@orcon.net.nz>
Signed-off-by: NKyle McMartin <kyle@redhat.com>
Signed-off-by: NMatt Turner <mattst88@gmail.com>