docker: Run tests with current user

We've used --add-current-user to create a user in the image, use it to
run tests, because root has too much priviledge, and can surprise test
cases.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170505032340.26467-2-famz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>

tests/docker/Makefile.include

@@ -126,7 +126,7 @@ docker-run: docker-qemu-src
 			"  COPYING $(EXECUTABLE) to $(IMAGE)"))
 	$(call quiet-command,						\
 		$(SRC_PATH)/tests/docker/docker.py run 			\
-			-t 						\
+			$(if $(NOUSER),,-u $(shell id -u)) -t 		\
 			$(if $V,,--rm) 					\
 			$(if $(DEBUG),-i,--net=none) 			\
 			-e TARGET_LIST=$(TARGET_LIST) 			\