staging: r8188eu: fix unused variable warnings in core/rtw_ieee80211.c

Remove an unused variable and a set but unused variable within
core/rtw_ieee80211.c to fix a kernel test robot warning.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210806004034.82233-11-phil@philpotter.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_ieee80211.c

@@ -626,7 +626,7 @@ int rtw_parse_wpa2_ie(u8 *rsn_ie, int rsn_ie_len, int *group_cipher, int *pairwi
 
 int rtw_get_sec_ie(u8 *in_ie, uint in_len, u8 *rsn_ie, u16 *rsn_len, u8 *wpa_ie, u16 *wpa_len)
 {
-	u8 authmode, sec_idx, i;
+	u8 authmode;
 	u8 wpa_oui[4] = {0x0, 0x50, 0xf2, 0x01};
 	uint	cnt;
 
@@ -634,8 +634,6 @@ int rtw_get_sec_ie(u8 *in_ie, uint in_len, u8 *rsn_ie, u16 *rsn_len, u8 *wpa_ie,
 
 	cnt = (_TIMESTAMP_ + _BEACON_ITERVAL_ + _CAPABILITY_);
 
-	sec_idx = 0;
-
 	while (cnt < in_len) {
 		authmode = in_ie[cnt];