PCI: xilinx-cpm: Fix reference count leak on error path

stable inclusion
from stable-5.10.20
commit 6a96a4413dcc85b09509f6fe87e74f9dd30cb2ce
bugzilla: 50608

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[ Upstream commit ae191d2e ]

Also drop the reference count of the node on error path.

Link: https://lore.kernel.org/r/20210120143745.699-1-bianpan2016@163.com


Fixes: 508f6106 ("PCI: xilinx-cpm: Add Versal CPM Root Port driver")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>