[libvirt] [PATCH] Fix > 1 char device for qemu VM

Trying to start a qemu guest with more than 1 character device (serial or parallel, doesn't count for console) always times out. There was an error in the code that would strip the pty path qemu spits out, which confused the parsing after being called more than twice. The attached patch fixes this. I verified that guests with 0, 1, and 2 serial devices all boot fine. Thanks, Cole