test: Correct operation when tests pass

When tests pass an error message is printed because of a variable that is
not initialised. Fix this.

Signed-off-by: Simon Glass <sjg@chromium.org>

test/run

@@ -3,9 +3,10 @@
 run_test() {
 	$@
 	[ $? -ne 0 ] && result=$((result+1))
-	echo "result $result"
 }
 
+result=0
+
 # Run all tests that the standard sandbox build can support
 run_test ./test/py/test.py --bd sandbox --build