kdump.conf: renew the path section
    
    In case no target is specified explicitly in /etc/kdump.conf, the behavior
    of path is changed, a check need be taken to see if any separate file
    system is mounted on any tier of 'path', and also to take the relevant
    action. Now the path section need be renewed for kdump.conf and its
    man page accordingly.
    
    Signed-off-by: Baoquan He <bhe@redhat.com>
    Acked-by: Vivek Goyal <vgoyal@redhat.com>