Bluetooth: zero kpp input for key generation

When generating new ECDH keys with kpp, the shared secret input needs to
be set to NULL. Fix this by including kpp_request_set_input call.

Fixes: 58771c1c ("Bluetooth: convert smp and selftest to crypto kpp
API")
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

net/bluetooth/ecdh_helper.c

@@ -191,6 +191,7 @@ bool generate_ecdh_keys(u8 public_key[64], u8 private_key[32])
 			goto free_all;
 
 		sg_init_one(&dst, tmp, 64);
+		kpp_request_set_input(req, NULL, 0);
 		kpp_request_set_output(req, &dst, 64);
 		kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 					 ecdh_complete, &result);