Bluetooth: Fix sending responses to identified L2CAP response packets

When L2CAP packets return a non-zero error and the value is passed
onwards by l2cap_bredr_sig_cmd this will trigger a command reject packet
to be sent. However, the core specification (page 1416 in core 4.0) says
the following: "Command Reject packets should not be sent in response to
an identified Response packet.".

This patch ensures that a command reject packet is not sent for any
identified response packet by ignoring the error return value from the
response handler functions.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

net/bluetooth/l2cap_core.c

@@ -5212,7 +5212,7 @@ static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
 
 	case L2CAP_CONN_RSP:
 	case L2CAP_CREATE_CHAN_RSP:
-		err = l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
+		l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
 		break;
 
 	case L2CAP_CONF_REQ:
@@ -5220,7 +5220,7 @@ static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
 		break;
 
 	case L2CAP_CONF_RSP:
-		err = l2cap_config_rsp(conn, cmd, cmd_len, data);
+		l2cap_config_rsp(conn, cmd, cmd_len, data);
 		break;
 
 	case L2CAP_DISCONN_REQ:
@@ -5228,7 +5228,7 @@ static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
 		break;
 
 	case L2CAP_DISCONN_RSP:
-		err = l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
+		l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
 		break;
 
 	case L2CAP_ECHO_REQ:
@@ -5243,7 +5243,7 @@ static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
 		break;
 
 	case L2CAP_INFO_RSP:
-		err = l2cap_information_rsp(conn, cmd, cmd_len, data);
+		l2cap_information_rsp(conn, cmd, cmd_len, data);
 		break;
 
 	case L2CAP_CREATE_CHAN_REQ:
@@ -5255,7 +5255,7 @@ static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
 		break;
 
 	case L2CAP_MOVE_CHAN_RSP:
-		err = l2cap_move_channel_rsp(conn, cmd, cmd_len, data);
+		l2cap_move_channel_rsp(conn, cmd, cmd_len, data);
 		break;
 
 	case L2CAP_MOVE_CHAN_CFM:
@@ -5263,7 +5263,7 @@ static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
 		break;
 
 	case L2CAP_MOVE_CHAN_CFM_RSP:
-		err = l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data);
+		l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data);
 		break;
 
 	default: