testrunner: use "#" for "test cases" suffix in .err filename too
This seems like a natural follow-up to
b865bba56db1 (run-tests: update
the test case name format, 2018-05-13).
Differential Revision: https://phab.mercurial-scm.org/D4052
fixbundle() {
grep -v 'saving bundle' | grep -v 'saved backup' | \
grep -v added | grep -v adding | \
grep -v "unable to find 'e' for patching" | \
grep -v "e: No such file or directory" | \
cat
}