support/testing: drop explicit CGROUPFS_MOUNT from docker test

Since commit 4f8229653 (package/docker-engine: needs more runtime
dependencies), docker-engine now automatically pulls in cgroupfs-mount, so
drop the explicit handling of it in TestDockerCompose.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 4726cf9517e35eaa9d08a3a4e9a5ac9cbb4da9e4)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

support/testing/tests/package/test_docker_compose.py

@@ -20,7 +20,6 @@ class TestDockerCompose(infra.basetest.BRTest):
         BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
         BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="{}"
         BR2_PACKAGE_CA_CERTIFICATES=y
-        BR2_PACKAGE_CGROUPFS_MOUNT=y
         BR2_PACKAGE_DOCKER_CLI=y
         BR2_PACKAGE_DOCKER_COMPOSE=y
         BR2_PACKAGE_DOCKER_ENGINE=y