wext: Emit event stream entries correctly when compat.

Three major portions to this change:

1) Add IW_EV_COMPAT_LCP_LEN, IW_EV_COMPAT_POINT_OFF,
   and IW_EV_COMPAT_POINT_LEN helper defines.

2) Delete iw_stream_check_add_*(), they are unused.

3) Add iw_request_info argument to iwe_stream_add_*(), and use it to
   size the event and pointer lengths correctly depending upon whether
   IW_REQUEST_FLAG_COMPAT is set or not.

4) The mechanical transformations to the drivers and wireless stack
   bits to get the iw_request_info passed down into the routines
   modified in #3.  Also, explicit references to IW_EV_LCP_LEN are
   replaced with iwe_stream_lcp_len(info).

With a lot of help and bug fixes from Masakazu Mokuno.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wireless/wl3501_cs.c b/drivers/net/wireless/wl3501_cs.c
index 42a36b3..3771419 100644
--- a/drivers/net/wireless/wl3501_cs.c
+++ b/drivers/net/wireless/wl3501_cs.c
@@ -1624,25 +1624,25 @@
 		iwe.cmd			= SIOCGIWAP;
 		iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
 		memcpy(iwe.u.ap_addr.sa_data, this->bss_set[i].bssid, ETH_ALEN);
-		current_ev = iwe_stream_add_event(current_ev,
+		current_ev = iwe_stream_add_event(info, current_ev,
 						  extra + IW_SCAN_MAX_DATA,
 						  &iwe, IW_EV_ADDR_LEN);
 		iwe.cmd		  = SIOCGIWESSID;
 		iwe.u.data.flags  = 1;
 		iwe.u.data.length = this->bss_set[i].ssid.el.len;
-		current_ev = iwe_stream_add_point(current_ev,
+		current_ev = iwe_stream_add_point(info, current_ev,
 						  extra + IW_SCAN_MAX_DATA,
 						  &iwe,
 						  this->bss_set[i].ssid.essid);
 		iwe.cmd	   = SIOCGIWMODE;
 		iwe.u.mode = this->bss_set[i].bss_type;
-		current_ev = iwe_stream_add_event(current_ev,
+		current_ev = iwe_stream_add_event(info, current_ev,
 						  extra + IW_SCAN_MAX_DATA,
 						  &iwe, IW_EV_UINT_LEN);
 		iwe.cmd = SIOCGIWFREQ;
 		iwe.u.freq.m = this->bss_set[i].ds_pset.chan;
 		iwe.u.freq.e = 0;
-		current_ev = iwe_stream_add_event(current_ev,
+		current_ev = iwe_stream_add_event(info, current_ev,
 						  extra + IW_SCAN_MAX_DATA,
 						  &iwe, IW_EV_FREQ_LEN);
 		iwe.cmd = SIOCGIWENCODE;
@@ -1651,7 +1651,7 @@
 		else
 			iwe.u.data.flags = IW_ENCODE_DISABLED;
 		iwe.u.data.length = 0;
-		current_ev = iwe_stream_add_point(current_ev,
+		current_ev = iwe_stream_add_point(info, current_ev,
 						  extra + IW_SCAN_MAX_DATA,
 						  &iwe, NULL);
 	}