travis: let "make travis" show the errors if any

Grep for FAIL in the log and print any errors, otherwise a success
message.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>

Author: H. Peter Anvin (Intel)

Makefile.in

@@ -61,6 +61,7 @@ EMPTY		= : >
 SIDE		= @: Generated by side effect
 
 PYTHON3		= @PYTHON3@
+GREP		= grep
 
 INSTALL		= @INSTALL@
 INSTALL_PROGRAM	= @INSTALL_PROGRAM@
@@ -578,7 +579,9 @@ $(travis_version): version
 	printf 'NASM version %s compiled on ?\n' `cat version` > $@
 
 travis: $(PROGS) $(travis_version)
-	$(PYTHON3) travis/nasm-t.py run > travis.log
+	-$(PYTHON3) travis/nasm-t.py run > travis.log
+	@if $(GREP) FAIL travis.log; then exit 1; else \
+		echo '=== All tests PASS ==='; fi
 
 #
 # Rules to run autogen if necessary