sandbox: add compression tests

This adds the "test_compression" command when building the sandbox. This
tests the existing compression and decompression routines for simple
sanity and for buffer overflow conditions.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/test/Makefile b/test/Makefile
index 99ce890..a68613d 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -9,6 +9,7 @@
 LIB	= $(obj)libtest.o
 
 COBJS-$(CONFIG_SANDBOX) += command_ut.o
+COBJS-$(CONFIG_SANDBOX) += compression.o
 
 COBJS	:= $(sort $(COBJS-y))
 SRCS	:= $(COBJS:.o=.c)