staging: rtl8188eu: convert variables from unsigned char to u8

Convert the local variables max_AMPDU_len and min_MPDU_spacing from
unsigned char to u8 and remove unnecessary castings to u8 pointer.
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20191003122514.1760-2-straube.linux@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_ap.c

@@ -560,8 +560,8 @@ void update_sta_info_apmode(struct adapter *padapter, struct sta_info *psta)
 
 static void update_hw_ht_param(struct adapter *padapter)
 {
-	unsigned char		max_AMPDU_len;
-	unsigned char		min_MPDU_spacing;
+	u8 max_AMPDU_len;
+	u8 min_MPDU_spacing;
 	struct mlme_ext_priv	*pmlmeext = &padapter->mlmeextpriv;
 	struct mlme_ext_info	*pmlmeinfo = &pmlmeext->mlmext_info;
 
@@ -576,9 +576,9 @@ static void update_hw_ht_param(struct adapter *padapter)
 
 	min_MPDU_spacing = (pmlmeinfo->HT_caps.ampdu_params_info & 0x1c) >> 2;
 
-	rtw_hal_set_hwreg(padapter, HW_VAR_AMPDU_MIN_SPACE, (u8 *)(&min_MPDU_spacing));
+	rtw_hal_set_hwreg(padapter, HW_VAR_AMPDU_MIN_SPACE, &min_MPDU_spacing);
 
-	rtw_hal_set_hwreg(padapter, HW_VAR_AMPDU_FACTOR, (u8 *)(&max_AMPDU_len));
+	rtw_hal_set_hwreg(padapter, HW_VAR_AMPDU_FACTOR, &max_AMPDU_len);
 
 	/*  */
 	/*  Config SM Power Save setting */