autotest/virt-test — pull request #1910 by cheliu (2014-12-05 04:12:29+00:00)
Title: Add error info when s4 is not available

s4 check could be failed because the rest of guest disk space is less than guest memory.
Will print rest of disk space and gest memory and free memory in the error info

Signed-off-by: Chengyou Liu