qcacld-3.0: Remove field connection from struct hdd_adapter

Field connection in struct hdd_adapter is unused, so remove it.

Change-Id: Ifb2898e5587b17454135181b054fb2bcd815ef88
CRs-Fixed: 2375422

core/hdd/inc/wlan_hdd_main.h

@@ -1329,7 +1329,6 @@ struct hdd_adapter {
 	unsigned long prev_tx_packets;
 	uint64_t prev_fwd_tx_packets;
 	uint64_t prev_fwd_rx_packets;
-	int connection;
 #endif
 #if  defined(QCA_LL_LEGACY_TX_FLOW_CONTROL) || \
 				defined(QCA_HL_NETDEV_FLOW_CONTROL)