tests: Solaris diff -U also emits "No differences encountered" This came up before, but the tests in check-code.py don't find -U (only -u) and they don't work when the diff is inside a shell function. This fixes the offending tests and beefs up check-code.py.

test-glog: avoid check-code violation after next patch Danek's patch will help us avoid spurious test breakages on Solaris. This test wasn't broken on Solaris because of the grep(1) use, but it will upset check-code. Use cmp to silence check-code since it doesn't matter.