fix parsing quoted kernel options
Quoted kernel options in /proc/cmdline look like this:
modules=something "ssh_key=ssh-rsa foobar user@foo" quiet
Without the eval this would be parsed as: opt='modules=something' opt='"ssh_key=ssh-rsa' opt='foobar' opt='user@foo"' opt='quiet'
With the eval in this branch the options are parsed correctly.
Since ssh keys need spaces and therefor must be quoted, passing ssh_key by kernel option cannot work as currently implemented.
Related issue: #9504 (closed)