RDMA/rxe: cleanup some error handling in rxe_verbs.c

Instead of 'goto and return', just return directly to
simplify the error handling, and avoid some unnecessary
return value check.

Link: https://lore.kernel.org/r/20221028075053.3990467-1-xuhaoyue1@hisilicon.com


Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Haoyue Xu <xuhaoyue1@hisilicon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>