Bluetooth: MGMT: fix zalloc-simple.cocci warnings

Use zeroing allocator rather than allocator followed by memset with 0

Generated by: scripts/coccinelle/api/alloc/zalloc-simple.cocci
Signed-off-by: Yihao Han <hanyihao@vivo.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

net/bluetooth/mgmt.c

@@ -4397,12 +4397,10 @@ static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
 
 	/* Enough space for 7 features */
 	len = sizeof(*rp) + (sizeof(rp->features[0]) * 7);
-	rp = kmalloc(len, GFP_KERNEL);
+	rp = kzalloc(len, GFP_KERNEL);
 	if (!rp)
 		return -ENOMEM;
 
-	memset(rp, 0, len);
-
 #ifdef CONFIG_BT_FEATURE_DEBUG
 	if (!hdev) {
 		flags = bt_dbg_get() ? BIT(0) : 0;