staging: r8188eu: Fix smatch warning in core/rtw_ieee80211.

Smatch shows the following warning:
drivers/staging/rtl8188eu/core/rtw_ieee80211.c:161 rtw_set_ie() info: ignoring unreachable code.

The cause is a module exit tracing statement after a return.
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_ieee80211.c

@@ -157,8 +157,8 @@ _func_enter_;
 
 	*frlen = *frlen + (len + 2);
 
-	return pbuf + len + 2;
 _func_exit_;
+	return pbuf + len + 2;
 }
 
 inline u8 *rtw_set_ie_ch_switch (u8 *buf, u32 *buf_len, u8 ch_switch_mode,