[bug report] qtnfmac: cleanup and unify command error handling

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

Hello Sergey Matyukevich,

The patch c6ed298ffe09: "qtnfmac: cleanup and unify command error
handling" from Oct 5, 2018, leads to the following static checker
warning:

	drivers/net/wireless/quantenna/qtnfmac/commands.c:132 qtnf_cmd_send_with_reply()
	warn: variable dereferenced before check 'resp' (see line 117)

drivers/net/wireless/quantenna/qtnfmac/commands.c
   112          ret = qtnf_trans_send_cmd_with_resp(bus, cmd_skb, &resp_skb);
   113          if (ret)
   114                  goto out;
   115  
   116          resp = (const struct qlink_resp *)resp_skb->data;
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   117          ret = qtnf_cmd_check_reply_header(resp, cmd_id, mac_id, vif_id,
                                                  ^^^^
Dereference

   118                                            const_resp_size);
   119          if (ret)
   120                  goto out;
   121  
   122          /* Return length of variable part of response */
   123          if (response_skb && var_resp_size)
   124                  *var_resp_size = le16_to_cpu(resp->mhdr.len) - const_resp_size;
   125  
   126  out:
   127          if (response_skb)
   128                  *response_skb = resp_skb;
   129          else
   130                  consume_skb(resp_skb);
   131  
   132          if (!ret && resp)
                            ^^^^
This new check is not required.

   133                  return qtnf_cmd_resp_result_decode(le16_to_cpu(resp->result));
   134  
   135          pr_warn("VIF%u.%u: cmd 0x%.4X failed: %d\n",
   136                  mac_id, vif_id, le16_to_cpu(cmd->cmd_id), ret);
   137  
   138          return ret;
   139  }

regards,
dan carpenter