staging: r8188eu: Fix sparse warnings regarding static functions

This fixes the following sparse warnings:
* drivers/staging/rtl8188eu/core/rtw_cmd.c:221:5: warning:
symbol 'rtw_cmd_filter' was not declared. Should it be static?
* drivers/staging/rtl8188eu/core/rtw_cmd.c:1670:6: warning:
symbol 'dynamic_chk_wk_hdl' was not declared. Should it be static?
Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_cmd.c

@@ -218,7 +218,7 @@ _func_enter_;
 _func_exit_;
 }
 
-int rtw_cmd_filter(struct cmd_priv *pcmdpriv, struct cmd_obj *cmd_obj)
+static int rtw_cmd_filter(struct cmd_priv *pcmdpriv, struct cmd_obj *cmd_obj)
 {
 	u8 bAllow = false; /* set to true to allow enqueuing cmd when hw_init_completed is false */
 
@@ -1667,7 +1667,7 @@ static void traffic_status_watchdog(struct adapter *padapter)
 	pmlmepriv->LinkDetectInfo.bHigherBusyTxTraffic = bHigherBusyTxTraffic;
 }
 
-void dynamic_chk_wk_hdl(struct adapter *padapter, u8 *pbuf, int sz)
+static void dynamic_chk_wk_hdl(struct adapter *padapter, u8 *pbuf, int sz)
 {
 	struct mlme_priv *pmlmepriv;