wil6210: fix warning in pointer arithmetic

In some compilation environments, result of pointer arithmetic interpreted as int
while in others it is long int. Force conversion to long.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/wil6210/fw_inc.c

@@ -446,7 +446,7 @@ static int wil_fw_load(struct wil6210_priv *wil, const void *data, size_t size)
 		if (size >= sizeof(*hdr)) {
 			wil_err_fw(wil, "Stop at offset %ld"
 				   " record type %d [%zd bytes]\n",
-				   (const void *)hdr - data,
+				   (long)((const void *)hdr - data),
 				   le16_to_cpu(hdr->type), hdr_sz);
 		}
 		return -EINVAL;