[bug report] RDMA/erdma: Add verbs implementation

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Cheng Xu,

The patch c4612e83c14b: "RDMA/erdma: Add verbs implementation" from
May 23, 2022, leads to the following Smatch static checker warning:

	drivers/infiniband/hw/erdma/erdma_verbs.c:111 create_qp_cmd()
	error: uninitialized symbol 'resp0'.

drivers/infiniband/hw/erdma/erdma_verbs.c
    100                 req.sq_buf_addr = user_qp->sq_mtt.mtt_entry[0];
    101                 req.rq_buf_addr = user_qp->rq_mtt.mtt_entry[0];
    102 
    103                 req.sq_db_info_dma_addr = user_qp->sq_db_info_dma_addr;
    104                 req.rq_db_info_dma_addr = user_qp->rq_db_info_dma_addr;
    105         }
    106 
    107         err = erdma_post_cmd_wait(&dev->cmdq, (u64 *)&req, sizeof(req), &resp0,
    108                                   &resp1);

The erdma_post_cmd_wait() function does not initialize erdma_post_cmd_wait()
on the error paths.

Also it returns comp_wait->comp_status which is a u8.  I guess that's
some kind of custom error code.  Mixing kernel and custom error codes
is dangerous.  I think it's a bug in this case.

    109 
    110         qp->attrs.cookie =
--> 111                 FIELD_GET(ERDMA_CMDQ_CREATE_QP_RESP_COOKIE_MASK, resp0);
    112 
    113         return err;
    114 }

regards,
dan carpenter