nvme-pci: always return an ERR_PTR from nvme_pci_alloc_dev

stable inclusion
from stable-v5.10.198
commit 831f18c735e2fc16bf7bfb1ec41cc30e6be9eb0f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I987V5

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=831f18c735e2fc16bf7bfb1ec41cc30e6be9eb0f



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[ Upstream commit dc785d69 ]

Don't mix NULL and ERR_PTR returns.

Fixes: 2e87570b ("nvme-pci: factor out a nvme_pci_alloc_dev helper")
Signed-off-by: Irvin Cote <irvin.cote@insa-lyon.fr>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>