When we updated the arguments for docker.py we missed a bit.
Fixes: dfae628459 ("docker.py/build: support -t and -f arguments")
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200724064509.331-11-alex.bennee@linaro.org>