The ps sched test has been disabled. There are too many
odd build farms this fails in strange ways.
Other odd build farms have no tty and so some tests check
for no tty and skip if not found.
Fix the build where it seems a code fix for Linux was likely untested
on other systems.
Define SCHED_BATCH in test-schedbatch, for systems that don't have it;
the corresponding RH BZ#741090 patch used the magic value 3 in output.c
anyway.
Bug-Debian: http://bugs.debian.org/677055
