doc: Fix texinfo @table markup in qemu-options.hx

doc: Fix texinfo @table markup in qemu-options.hx

End tables before headings, start new ones afterwards.  Fixes
incorrect indentation of headings "File system options" and "Virtual
File system pass-through options" in manual page and qemu-doc.

Normalize markup some to increase chances it survives future edits.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1360781383-28635-5-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>