Bluetooth: mgmt: Add new error code for invalid index

The index is part of the command header and not its parameters so it
makes sense to distinguish this from the invalid parameters error.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/mgmt.h

@@ -41,6 +41,7 @@
 #define MGMT_STATUS_DISCONNECTED	0x0e
 #define MGMT_STATUS_NOT_POWERED		0x0f
 #define MGMT_STATUS_CANCELLED		0x10
+#define MGMT_STATUS_INVALID_INDEX	0x11
 
 struct mgmt_hdr {
 	__le16 opcode;