Remove some more tests from the "auto" group that either have issues
in certain environments (like macOS or FreeBSD, or on certain file systems
like ZFS or tmpfs), do not work with the qcow2 format, or that are simply
taking too much time.

Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190717111947.30356-3-thuth@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>