LU-4961 build: remove libsysio and liblustre autoconf tests

LU-4961 build: remove libsysio and liblustre autoconf tests

Remove the libsysio and liblustre tests from config/lustre-build.m4,
lnet/autoconf/lustre-lnet.m4, and lustre/autoconf/lustre-core.m4,
leaving a temporary AM_CONDITIONAL(LIBLUSTRE, false) in their
place. Remove related bits from lustre-spec.in and debian/rules.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I9483bc9114fa0682b84e6a9014123e5838f1c1a7
Reviewed-on: http://review.whamcloud.com/10201
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Brian J. Murrell <brian.murrell@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>