nvme: clear any SGL flags in passthru commands

mainline inclusion
from mainline-v5.9-rc1
commit 2bf5d3bb
category: bugfix
bugzilla: NA
CVE: NA
Link: https://gitee.com/openeuler/kernel/issues/I1WGZE



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

The host driver should decide whether to use SGLs or PRPs and they
currently assume the flags are cleared after the call to
nvme_setup_cmd(). However, passed-through commands may erroneously
set these bits; so clear them for all cases.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Leng <lengchao@huawei.com>
Reviewed-by: Jike Cheng <chengjike.cheng@huawei.com>
Signed-off-by: Lijie <lijie34@huawei.com>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>