Staging: rtl8723bs: core: remove set but not used 'ptxservq'

Fix the following gcc warning:

drivers/staging/rtl8723bs/core/rtw_sta_mgt.c:556:19: warning: variable
‘ptxservq’ set but not used [-Wunused-but-set-variable]
  struct tx_servq *ptxservq;
                   ^~~~~~~~

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200427032342.27211-4-yanaijie@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/core/rtw_sta_mgt.c

@@ -553,7 +553,6 @@ u32 rtw_init_bcmc_stainfo(struct adapter *padapter)
 {
 
 	struct sta_info *psta;
-	struct tx_servq	*ptxservq;
 	u32 res = _SUCCESS;
 	NDIS_802_11_MAC_ADDRESS	bcast_addr = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 
@@ -571,7 +570,6 @@ u32 rtw_init_bcmc_stainfo(struct adapter *padapter)
 	/*  default broadcast & multicast use macid 1 */
 	psta->mac_id = 1;
 
-	ptxservq = &(psta->sta_xmitpriv.be_q);
 exit:
 	return _SUCCESS;
 }