Bluetooth: Use kzalloc instead of kmalloc/memset

Use kzalloc rather than duplicating its implementation, which makes code
simple and easy to understand.

./net/bluetooth/hci_conn.c:2038:6-13: WARNING: kzalloc should be used for cp, instead of kmalloc/memset.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2406Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

net/bluetooth/hci_conn.c

@@ -2046,13 +2046,12 @@ int hci_pa_create_sync(struct hci_dev *hdev, bdaddr_t *dst, __u8 dst_type,
 	if (hci_dev_test_and_set_flag(hdev, HCI_PA_SYNC))
 		return -EBUSY;
 
-	cp = kmalloc(sizeof(*cp), GFP_KERNEL);
+	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
 	if (!cp) {
 		hci_dev_clear_flag(hdev, HCI_PA_SYNC);
 		return -ENOMEM;
 	}
 
-	memset(cp, 0, sizeof(*cp));
 	cp->sid = sid;
 	cp->addr_type = dst_type;
 	bacpy(&cp->addr, dst);