kdump: Remove kexec-tools check from offlinepackager

Removes kexec-tools package check from offlinepackager, so for now kdump
detection is completely disabled for oVirt Node hosts.

Change-Id: I7d53b0467f8f2663f42a7665e1cfe611ca66546f
Bug-Url: https://bugzilla.redhat.com/1079821
Signed-off-by: Martin Perina <mperina@redhat.com>