RDMA/rtrs: Fix the last iu->buf leak in err path

stable inclusion
from stable-v5.10.185
commit cb6ec51ddd00aa8768e0b7d24a8d3b189bf52837
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8L5XP

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cb6ec51ddd00aa8768e0b7d24a8d3b189bf52837

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

[ Upstream commit 3bf3a7c6 ]

The last iu->buf will leak if ib_dma_mapping_error() fails.

Fixes: c0894b3e ("RDMA/rtrs: core: lib functions shared between client and server modules")
Link: https://lore.kernel.org/r/1682384563-2-3-git-send-email-lizhijian@fujitsu.com


Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>