powernv/opal-irqchip: Fix double endian conversion

[Michael Ellerman]

On Mon, 2015-07-12 at 00:28:28 UTC, Alistair Popple wrote:
> The OPAL event calls return a mask of events that are active in big
> endian format. This is checked when unmasking the events in the
> irqchip by comparison with a cached value. The cached value was stored
> in big endian format but should've been converted to CPU endian
> first. This bug leads to OPAL event delivery being delayed or dropped
> on some systems.
> 
> The bug is fixed by calling opal_handle_events(...) instead of
> duplicating code in opal_event_unmask(...).
> 
> Signed-off-by: Alistair Popple <alistair at popple.id.au>
> Reported-by: Douglas L Lehr <dllehr at us.ibm.com>
> Cc: stable at vger.kernel.org

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/25642e1459ace29f6ce5a171

cheers