SetupTest could fail creating a Daemon object (eg, out of space when
creating daemon root dir). In such a case, TearDownTest fails when
accessing the daemon object. This commit adds the required nil check.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
Upstream-commit: 5890091cc02ca75425c8635cbe4ec6c7ccd1663b
Component: engine