staging: r8188eu: make ips_enter static

The ips_enter function is used only in rtw_pwrctrl.c. We can make this
function static.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Link: https://lore.kernel.org/r/20230206210124.150142-2-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_pwrctrl.c

@@ -8,7 +8,7 @@
 #include "../include/osdep_intf.h"
 #include "../include/linux/usb.h"
 
-void ips_enter(struct adapter *padapter)
+static void ips_enter(struct adapter *padapter)
 {
 	struct pwrctrl_priv *pwrpriv = &padapter->pwrctrlpriv;
 	struct xmit_priv *pxmit_priv = &padapter->xmitpriv;

drivers/staging/r8188eu/include/rtw_pwrctrl.h

@@ -99,7 +99,6 @@ void rtw_set_firmware_ps_mode(struct adapter *adapter, u8 mode);
 void rtw_set_ps_mode(struct adapter *adapter, u8 ps_mode, u8 smart_ps,
 		     u8 bcn_ant_mode);
 void LeaveAllPowerSaveMode(struct adapter *adapter);
-void ips_enter(struct adapter *padapter);
 int ips_leave(struct adapter *padapter);
 
 void rtw_ps_processor(struct adapter *padapter);