Add test failure check in FPGA test script

OT test framework has logs for test pass/fail. Add checks for both cases
so we can exit the test script early in a failed run.

See https://github.com/lowRISC/opentitan/blob/master/sw/device/lib/testing/test_framework/status.c

Change-Id: I310f8a7435b85e477f1fb804479f9d145d4261f1

nexus-non-interactive-test.sh

diff --git a/nexus-non-interactive-test.sh b/nexus-non-interactive-test.sh
index ffe195f..411d605 100755
--- a/nexus-non-interactive-test.sh
+++ b/nexus-non-interactive-test.sh
@@ -96,10 +96,10 @@
 fi
 
 timeout "${LOG_TIMEOUT}" bash -c '
-    until grep -q PASS! uart.sc.log uart.smc.log ; do
+    until grep -q -e PASS! -e FAIL! uart.sc.log uart.smc.log ; do
         echo "Expected log is missing. Wait up to ${LOG_TIMEOUT}s."
         sleep "${LOG_CHECK_INTERVAL}"
-    done' || echo "Time out waiting for PASS! log"
+    done' || echo "Time out waiting for PASS! or FAIL! log"
 
 cat -n uart.sc.log
 cat -n uart.smc.log