mwifiex: remove wireless.h inclusion and fix resulting bugs

replace IW_MAX_AP & IW_CUSTOM_MAX with local definitions
and remove usage of struct iw_statistics.

Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/sta_event.c b/drivers/net/wireless/mwifiex/sta_event.c
index fc265ca..6e8b198 100644
--- a/drivers/net/wireless/mwifiex/sta_event.c
+++ b/drivers/net/wireless/mwifiex/sta_event.c
@@ -130,8 +130,8 @@
 	if (netif_carrier_ok(priv->netdev))
 		netif_carrier_off(priv->netdev);
 	/* Reset wireless stats signal info */
-	priv->w_stats.qual.level = 0;
-	priv->w_stats.qual.noise = 0;
+	priv->qual_level = 0;
+	priv->qual_noise = 0;
 }
 
 /*
@@ -301,7 +301,7 @@
 		dev_dbg(adapter->dev, "event: BGS_REPORT\n");
 		/* Clear the previous scan result */
 		memset(adapter->scan_table, 0x00,
-		       sizeof(struct mwifiex_bssdescriptor) * IW_MAX_AP);
+		       sizeof(struct mwifiex_bssdescriptor) * MWIFIEX_MAX_AP);
 		adapter->num_in_scan_table = 0;
 		adapter->bcn_buf_end = adapter->bcn_buf;
 		ret = mwifiex_send_cmd_async(priv,