brcmfmac: assure bcdc dcmd api does not return value > 0

The protocol layer api defines callbacks for dongle commands.
Although not really well documented these should only return an
error code in case of an error, or 0 upon success. In the bcdc
protocol it can return value above 0 and we carry a fix in the
caller of the protocol layer api. This patch makes it adhere to
the intent of the api as described above.
Reviewed-by: NHante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: NPieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: NFranky Lin <franky.lin@broadcom.com>
Signed-off-by: NArend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcdc.c

@@ -211,6 +211,8 @@ brcmf_proto_bcdc_query_dcmd(struct brcmf_pub *drvr, int ifidx, uint cmd,
 		memcpy(buf, info, len);
 	}
 
+	ret = 0;
+
 	/* Check the ERROR flag */
 	if (flags & BCDC_DCMD_ERROR)
 		ret = le32_to_cpu(msg->status);
@@ -225,7 +227,7 @@ brcmf_proto_bcdc_set_dcmd(struct brcmf_pub *drvr, int ifidx, uint cmd,
 {
 	struct brcmf_bcdc *bcdc = (struct brcmf_bcdc *)drvr->proto->pd;
 	struct brcmf_proto_bcdc_dcmd *msg = &bcdc->msg;
-	int ret = 0;
+	int ret;
 	u32 flags, id;
 
 	brcmf_dbg(BCDC, "Enter, cmd %d len %d\n", cmd, len);
@@ -249,6 +251,8 @@ brcmf_proto_bcdc_set_dcmd(struct brcmf_pub *drvr, int ifidx, uint cmd,
 		goto done;
 	}
 
+	ret = 0;
+
 	/* Check the ERROR flag */
 	if (flags & BCDC_DCMD_ERROR)
 		ret = le32_to_cpu(msg->status);

drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil.c

@@ -121,11 +121,9 @@ brcmf_fil_cmd_data(struct brcmf_if *ifp, u32 cmd, void *data, u32 len, bool set)
 	else
 		err = brcmf_proto_query_dcmd(drvr, ifp->ifidx, cmd, data, len);
 
-	if (err >= 0)
-		return 0;
-
-	brcmf_dbg(FIL, "Failed: %s (%d)\n",
-		  brcmf_fil_get_errstr((u32)(-err)), err);
+	if (err)
+		brcmf_dbg(FIL, "Failed: %s (%d)\n",
+			  brcmf_fil_get_errstr((u32)(-err)), err);
 
 	return err;
 }