We are going to enable the qemu-iotests during "make check" again,
and for running the iotests, we need bash and gnu-sed.

Reviewed-by: Li-Wen Hsu <lwhsu@freebsd.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20190502084506.8009-5-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>