improve error "Device is not available: No such device" of hcitool scan

[Karl-Philipp Richter]

The feedback `Device is not available: No such device` of `hcitool scan` is unhelpful and should be replaced with a feedback explaining the state (at least which device isn't there) and instructions how fix it.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: bluez 4.101-0ubuntu25
Uname: Linux 4.0.1-040001-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
CurrentDesktop: Unity
Date: Sat May 23 21:31:08 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-04-02 (50 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Beta amd64 (20150326)
InterestingModules: rfcomm bnep btusb bluetooth
MachineType: LENOVO 20221
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.0.1-040001-generic root=UUID=0d646fdd-bb34-4e1c-9271-86a59deb3bf9 ro rootflags=subvol=@
SourcePackage: bluez
SystemImageInfo:
 current build number: 0
 device name:
 channel: daily
 last update: Unknown
UdevLog: Error: [Errno 2] Datei oder Verzeichnis nicht gefunden: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/12/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 71CN51WW(V1.21)
dmi.board.asset.tag: No Asset Tag
dmi.board.name: INVALID
dmi.board.vendor: LENOVO
dmi.board.version: 31900003WIN8 STD MLT
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo IdeaPad Z500 Touch
dmi.modalias: dmi:bvnLENOVO:bvr71CN51WW(V1.21):bd07/12/2013:svnLENOVO:pn20221:pvrLenovoIdeaPadZ500Touch:rvnLENOVO:rnINVALID:rvr31900003WIN8STDMLT:cvnLENOVO:ct10:cvrLenovoIdeaPadZ500Touch:
dmi.product.name: 20221
dmi.product.version: Lenovo IdeaPad Z500 Touch
dmi.sys.vendor: LENOVO
hciconfig:
 hci0: Type: BR/EDR Bus: USB
  BD Address: 68:17:29:77:05:46 ACL MTU: 310:10 SCO MTU: 64:8
  DOWN
  RX bytes:34853 acl:308 sco:0 events:1087 errors:0
  TX bytes:10432 acl:322 sco:0 commands:265 errors:0

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu. Ubuntu 15.04 (vivid) reached end-of-life on February 4, 2016.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

Please upgrade to the latest version and re-test.

[Launchpad Janitor (janitor)]

[Expired for bluez (Ubuntu) because there has been no activity for 60 days.]