kdump: copy kernel from /boot for iscsi installs.

rhbz#885960
Bug-Url:https://bugzilla.redhat.com/show_bug.cgi?id=885960
Signed-off-by: Joey Boggs <jboggs@redhat.com>
Signed-off-by: hadong <hadong0720@gmail.com>
Change-Id: I60c9b832e10e6e4ae0ba1a7a4e370f95525553e7