autotest/virt-test — pull request #1921 by will-Do (2014-12-11 08:14:08+00:00)
Title: get volume virtual size correctly

For some format volume(vmdk, etc.), 'qemu-img info' output looks like:
$ qemu-img info /tmp/vmdk-v4.img
image: /tmp/vmdk-v4.img
file format: vmdk
virtual size: 1.0M (1048576 bytes)
disk size: 12K
cluster_size: 65536
Format specific information:
cid: 1418280048
parent cid: 4294967295
create type: monolithicSparse
extents:
[0]:
virtual size: 1048576
filename: /tmp/vmdk-v4.img
cluster size: 65536
format:

and only the first line of 'virtual size' is what we want.

Signed-off-by: Yanbing Du