irqchip/gic-v3-its: Fix potential VPE leak on error

stable inclusion
from linux-4.19.209
commit 5701e8bff314c155e7afdc467b1e0389d86853d0

--------------------------------

[ Upstream commit 280bef51 ]

In its_vpe_irq_domain_alloc, when its_vpe_init() returns an error,
there is an off-by-one in the number of VPEs to be freed.

Fix it by simply passing the number of VPEs allocated, which is the
index of the loop iterating over the VPEs.

Fixes: 7d75bbb4 ("irqchip/gic-v3-its: Add VPE irq domain allocation/teardown")
Signed-off-by: Kaige Fu <kaige.fu@linux.alibaba.com>
[maz: fixed commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/d9e36dee512e63670287ed9eff884a5d8d6d27f2.1631672311.git.kaige.fu@linux.alibaba.com


Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>