LU-9222 build: workaround for sles11sp4 MOFED

LU-9222 build: workaround for sles11sp4 MOFED

MOFED assume that kernel-source is in the
standard place /usr/src but lbuild is using
different directory

Change-Id: I236659baf344cb3b3dcb62840c576c55febc1523
Signed-off-by: Minh Diep <minh.diep@intel.com>
Reviewed-on: https://review.whamcloud.com/26045
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>