Staging: rtl8192u: fix functions that should not be declared extern

These functions are already marked extern in the header file

drivers/staging/rtl8192u/r819xU_phy.c:1716:13: warning: function 'InitialGainOperateWorkItemCallBack' with external linkage has definition
drivers/staging/rtl8192u/r819xU_cmdpkt.c:497:12: warning: function 'cmpk_message_handle_rx' with external linkage has definition

Signed-off-by: Teodora Baluta <teobaluta@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192u/r819xU_cmdpkt.c

@@ -494,8 +494,8 @@ static void cmpk_handle_tx_rate_history(struct net_device *dev, u8 *pmsg)
  *  05/06/2008		amy	Create Version 0 porting from windows code.
  *
  *---------------------------------------------------------------------------*/
-extern u32 cmpk_message_handle_rx(struct net_device *dev,
-				  struct ieee80211_rx_stats *pstats)
+u32 cmpk_message_handle_rx(struct net_device *dev,
+			   struct ieee80211_rx_stats *pstats)
 {
 	int			total_length;
 	u8			cmd_length, exe_cnt = 0;

drivers/staging/rtl8192u/r819xU_phy.c

@@ -1713,7 +1713,7 @@ void InitialGain819xUsb(struct net_device *dev,	u8 Operation)
 		queue_delayed_work(priv->priv_wq, &priv->initialgain_operate_wq, 0);
 }
 
-extern void InitialGainOperateWorkItemCallBack(struct work_struct *work)
+void InitialGainOperateWorkItemCallBack(struct work_struct *work)
 {
 	struct delayed_work *dwork = container_of(work, struct delayed_work,
 						  work);