RDMA/erdma: Fix ignored return value of init_kernel_qp

RDMA/erdma: Fix ignored return value of init_kernel_qp

[ Upstream commit d5c74713f0117d07f91eb48b10bc2ad44e23c9b9 ]

The init_kernel_qp interface may fail. Check its return value and free
related resources properly when it does.

Fixes: 155055771704 ("RDMA/erdma: Add verbs implementation")
Reviewed-by: Cheng Xu <chengyou@linux.alibaba.com>
Signed-off-by: Boshi Yu <boshiyu@linux.alibaba.com>
Link: https://patch.msgid.link/20250725055410.67520-3-boshiyu@linux.alibaba.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>