Bluetooth: Use kzalloc instead of kmalloc for pending mgmt commands

By using kzalloc we ensure that there are no struct members, such as the
user_data pointer, left uninitialized.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/mgmt.c

@@ -984,7 +984,7 @@ static struct pending_cmd *mgmt_pending_add(struct sock *sk, u16 opcode,
 {
 	struct pending_cmd *cmd;
 
-	cmd = kmalloc(sizeof(*cmd), GFP_KERNEL);
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 	if (!cmd)
 		return NULL;