do not hide compression, only ignore errors

Makefile

@@ -15,10 +15,10 @@ fclean: clean
 test: rand
 	./rand | dd of=/dev/null bs=1M count=1000
 	./rand | dd of=test.bin bs=1M count=10
-	@gzip -9 < test.bin > test.gz
+	-gzip -9 < test.bin > test.gz
 	./checksize test.bin test.gz
-	@bzip2 -9 < test.bin > test.bz
+	-bzip2 -9 < test.bin > test.bz
 	./checksize test.bin test.bz
-	@xz -9 < test.bin > test.xz
+	-xz -9 < test.bin > test.xz
 	./checksize test.bin test.xz
 	rm -f $(TESTFILES)