tests/int/cgroups.bats: rm unused code

Commit d78ae51a2 adds this line, but the file is never created.

This is probably a leftover from copy-pasting update.bats code.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

tests/integration/cgroups.bats

@@ -3,7 +3,6 @@
 load helpers
 
 function teardown() {
-    rm -f "$BATS_TMPDIR"/runc-cgroups-integration-test.json
     teardown_running_container test_cgroups_kmem
     teardown_running_container test_cgroups_permissions
     teardown_busybox