kexec-tools-el6: Version 2.0.0-273.1 with fence_kdump patches

Applies fence_kdump patches to kexec-tools-2.0.0-273 (part of RHEL 6.5)
so package can be provided by oVirt repository until RHEL 6.6 is
released (which will contain kexec-tools-2.0.0-274 with fence_kdump
patches).

Change-Id: Ie555465cd7cd39c6e6fa5d9c65733823c12ddc4b
Signed-off-by: Martin Perina <mperina@redhat.com>