LU-2503 libcfs: Call lbug_with_loc() in LASSERT()

LU-2503 libcfs: Call lbug_with_loc() in LASSERT()

LASSERT() declares a msgdata which can be passed to lbug_with_loc()
instead of calling LBUG() thereby saving /millions/ of bytes.  Also
remove unused libcfs_assertion_failed().

Signed-off-by: John L. Hammond <jhammond@tacc.utexas.edu>
Change-Id: Iac267c7804b5e18f687f47b2eea585c655e7bb21
Reviewed-on: http://review.whamcloud.com/4844
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>