usleep: use it to simplify tests Blindly using usleep makes it easier to write tests. * modules/stat-time-tests (Depends-on): Add usleep. (configure.ac): Drop usleep check. * modules/chown-tests (Depends-on, configure.ac): Likewise. * modules/lchown-tests (Depends-on, configure.ac): Likewise. * modules/fdutimensat-tests (Depends-on, configure.ac): Likewise. * modules/futimens-tests (Depends-on, configure.ac): Likewise. * modules/openat-tests (Depends-on, configure.ac): Likewise. * modules/utimens-tests (Depends-on, configure.ac): Likewise. * modules/utimensat-tests (Depends-on, configure.ac): Likewise. * modules/pipe-filter-gi-tests (Depends-on, configure.ac): Likewise. * tests/test-chown.h (nap): Rely on nicer usleep semantics. * tests/test-lchown.h (nap): Likewise. * tests/test-pipe-filter-gi2-main.c (small_nap): Likewise. * tests/test-stat-time.c (nap): Likewise. * tests/test-utimens-common.h (nap): Update comments. Signed-off-by: Eric Blake <ebb9@byu.net>