qemu.tests: update max_memory to keep guest from oom in ksm_base

As the scripts will use some extra memory in guest. So include that when
calculate the max memory can be used for test.

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
qemu.tests: Remove unreadable codes from linux console in seabios

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
virttest: Record command output for compare_image in qemu_storage

Record the compare command in debug file for further analyse.

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
qemu.tests.cfg: Make floppy_test support Windows guests

As already have the command for Window guests in guest-os cfg files,
remove the only Linux in floppy_test.cfg. And the mount_dir is
a parameter only for Linux guest. So remove the force requirement
for the parameter.

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
Merge pull request #1128 from ypu/bugfix

Some small bug fixes for qemu tests (floppy, ksm_base, seabios).