virt-test: Replace the line break of info numa with "\n"

In different version of qemu, the output of info numa is different.
So we need replace the line break with "\n" so the pattern can
actually work.

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
Merge pull request #1814 from ypu/numa-info

virt-test: Replace the line break of info numa with "\n"