dracut-kdump.sh: Execute the binary and script filesin /etc/kdump/{pre.d,post.d}
    
    This patch executes the binary and script files in /etc/kdump/{pre.d,post.d}
    just like kdump_pre or kdump_post directive written in /etc/kdump.conf.
    
    Signed-off-by: Shinichi Onitsuka <onitsuka.shinic@fujitsu.com>
    Acked-by: Pingfan Liu <piliu@redhat.com>