Ensure flushing of IO prior to removing FC device

This patch flushes IO for each SCSI device that
brick removes from the system.  The patch also
flushes a multipath device prior to removing
each underlying LUN associated with the
multipath device.   We were seeing kernel
IO errors in the syslog without calling flush
on the block device, during a detach for a
multipath FibreChannel copy image to volume
action.

Change-Id: I2fae3dccd4fcab22c8f59dcd297581ee9577b779
Closes-Bug: 1318950
Delete image on upload-to-image failure

On upload-to-image failure before initiating the data transfer or during
data transfer, the source volume status is restored properly whereas the
image created remains in queued or saving state. This change deletes the
image during such failures.

Change-Id: I0aa64798d2bc5bf19b79dd3b88dcd107ff369c42
Closes-Bug: #1298042
Merge "Ensure flushing of IO prior to removing FC device"