check: Allow partial test names

check: Allow partial test names

When running ./check and calling a test with a name, id is enough
to find the test (names added in 03c633bf).

If the full test path is tests/xfs/123-foo-bar, then all these
invocations should work, as long as the given part of the test name
is valid and the three-digits id is here.

./check xfs/123-foo-bar
./check xfs/123-foo
./check xfs/123

Always use full test name in results.

Signed-off-by: Jan Tulak <jtulak@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>