drivers/net/wireless/wl12xx: Use available error codes

In each case, error codes are stored in ret, but the return value is always
0.  Return ret instead.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
local idexpression x;
constant C;
@@

if (...) { ...
  x = -C
  ... when != x
(
  return <+...x...+>;
|
  return NULL;
|
  return;
|
* return ...;
)
}
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Kalle Valo <kvalo@adurom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/wl12xx/wl1251_acx.c

@@ -380,7 +380,7 @@ int wl1251_acx_pd_threshold(struct wl1251 *wl)
 
 out:
 	kfree(pd);
-	return 0;
+	return ret;
 }
 
 int wl1251_acx_slot(struct wl1251 *wl, enum acx_slot_type slot_time)

drivers/net/wireless/wl12xx/wl1251_cmd.c

@@ -200,7 +200,7 @@ int wl1251_cmd_vbm(struct wl1251 *wl, u8 identity,
 
 out:
 	kfree(vbm);
-	return 0;
+	return ret;
 }
 
 int wl1251_cmd_data_path(struct wl1251 *wl, u8 channel, bool enable)