virt plugin: Fix memory stats to use the same units

memory_submit and memory_stats_submit should use same units "Bytes"

- Fixes: #856
Merge pull request #857 from Lupul/patch-1

virt plugin: Fix memory stats to use the same units

For the record, this is the same as 7bf99b36d, which got missed out from 627a050790.
Merge branch 'master' into debian
updating build.sh results
Merge branch "debian" into debian-wheezy-backports