test: Add a test for snprintf() and the banner/version

Add a simple test to make sure that these functions obey the buffer size
passed into them.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
diff --git a/test/Makefile b/test/Makefile
index 0f5de57..6305afb 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -8,4 +8,5 @@
 obj-$(CONFIG_UNIT_TEST) += ut.o
 obj-$(CONFIG_SANDBOX) += command_ut.o
 obj-$(CONFIG_SANDBOX) += compression.o
+obj-$(CONFIG_SANDBOX) += print_ut.o
 obj-$(CONFIG_UT_TIME) += time_ut.o