Merge remote-tracking branch 'luiz/queue/qmp' into staging

# By Luiz Capitulino
# Via Luiz Capitulino
* luiz/queue/qmp:
  qerror: drop QERR_OPEN_FILE_FAILED macro
  block: bdrv_reopen_prepare(): don't use QERR_OPEN_FILE_FAILED
  savevm: qmp_xen_save_devices_state(): use error_setg_file_open()
  dump: qmp_dump_guest_memory(): use error_setg_file_open()
  cpus: use error_setg_file_open()
  blockdev: use error_setg_file_open()
  block: mirror_complete(): use error_setg_file_open()
  rng-random: use error_setg_file_open()
  error: add error_setg_file_open() helper

Message-id: 1371484631[email protected]
Signed-off-by: Anthony Liguori <[email protected]>