staging: rtl8723bs: os_dep: ioctl_linux: make use of kzalloc

This patch is a cleanup which replaces rtw_malloc(wep_total_len) with
kzalloc() and removes the memset().

The rtw_malloc() does GFP_ATOMIC allocations when in_atomic() is true.
But as the comments for in_atomic() describe, the in_atomic() check
should not be used in driver code.  The in_atomic() check is not
accurate when preempt is disabled.

In this code we are not in IRQ context and we are not holding any
spin_locks so GFP_KERNEL is safe.
Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
----
changes in v2: Replace rtw_zmalloc with kzalloc
changes in v3: Add proper changelog
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/os_dep/ioctl_linux.c

@@ -477,14 +477,12 @@ static int wpa_set_encryption(struct net_device *dev, struct ieee_param *param,
 		if (wep_key_len > 0) {
 			wep_key_len = wep_key_len <= 5 ? 5 : 13;
 			wep_total_len = wep_key_len + FIELD_OFFSET(struct ndis_802_11_wep, KeyMaterial);
-			pwep = rtw_malloc(wep_total_len);
+			pwep = kzalloc(wep_total_len, GFP_KERNEL);
 			if (pwep == NULL) {
 				RT_TRACE(_module_rtl871x_ioctl_os_c, _drv_err_, (" wpa_set_encryption: pwep allocate fail !!!\n"));
 				goto exit;
 			}
 
-			memset(pwep, 0, wep_total_len);
-
 			pwep->KeyLength = wep_key_len;
 			pwep->Length = wep_total_len;
 
@@ -2142,12 +2140,10 @@ static int rtw_wx_set_enc_ext(struct net_device *dev,
 	int ret = 0;
 
 	param_len = sizeof(struct ieee_param) + pext->key_len;
-	param = rtw_malloc(param_len);
+	param = kzalloc(param_len, GFP_KERNEL);
 	if (param == NULL)
 		return -1;
 
-	memset(param, 0, param_len);
-
 	param->cmd = IEEE_CMD_SET_ENCRYPTION;
 	memset(param->sta_addr, 0xff, ETH_ALEN);
 
@@ -3513,14 +3509,12 @@ static int rtw_set_encryption(struct net_device *dev, struct ieee_param *param,
 		if (wep_key_len > 0) {
 			wep_key_len = wep_key_len <= 5 ? 5 : 13;
 			wep_total_len = wep_key_len + FIELD_OFFSET(struct ndis_802_11_wep, KeyMaterial);
-			pwep = rtw_malloc(wep_total_len);
+			pwep = kzalloc(wep_total_len, GFP_KERNEL);
 			if (pwep == NULL) {
 				DBG_871X(" r871x_set_encryption: pwep allocate fail !!!\n");
 				goto exit;
 			}
 
-			memset(pwep, 0, wep_total_len);
-
 			pwep->KeyLength = wep_key_len;
 			pwep->Length = wep_total_len;