btrfs-progs: tests: rename test 001 to mention check

Make it more clear that the test does 'btrfs check'.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/tests/fuzz-tests/001-simple-unmounted/test.sh b/tests/fuzz-tests/001-simple-check-unmounted/test.sh
similarity index 100%
rename from tests/fuzz-tests/001-simple-unmounted/test.sh
rename to tests/fuzz-tests/001-simple-check-unmounted/test.sh