Don't pipe check-fast results through tee

This was having the effect of scrubbing failure error codes. The only affect
of removing this should be that the .out file isn't generated, so subsequent
make invocations will re-run the tests (which is how our other tests work
anyway).

Author: brson

mk/tests.mk

@@ -329,4 +329,4 @@ test/$(FT_DRIVER)$(X): test/$(FT_DRIVER).rs stage2/lib/$(FT_LIB) $(SREQ2)
 	$(STAGE2) -o $@ $<
 
 test/$(FT_DRIVER).out: test/$(FT_DRIVER)$(X) $(SREQ2)
-	$(Q)$(call CFG_RUN_TEST, $<) | tee $@
+	$(Q)$(call CFG_RUN_TEST, $<)