Simplify test failure detection in %check

There is the same logic in the upstream script:
https://hg.mozilla.org/projects/nss/file/tip/tests/common/cleanup.sh#l56

nss.spec

@@ -43,7 +43,7 @@ rpm.define(string.format("nss_release_tag NSS_%s_RTM",
 Summary:          Network Security Services
 Name:             nss
 Version:          %{nss_version}
-Release:          4%{?dist}
+Release:          5%{?dist}
 License:          MPLv2.0
 URL:              http://www.mozilla.org/projects/security/pki/nss/
 Requires:         nspr >= %{nspr_version}
@@ -478,35 +478,7 @@ pushd nss/tests
 HOST=localhost DOMSUF=localdomain PORT=$MYRAND NSS_CYCLES=%{?nss_cycles} NSS_TESTS=%{?nss_tests} NSS_SSL_TESTS=%{?nss_ssl_tests} NSS_SSL_RUN=%{?nss_ssl_run} ./all.sh
 popd
 
-# Normally, the grep exit status is 0 if selected lines are found and 1 otherwise,
-# Grep exits with status greater than 1 if an error ocurred.
-# If there are test failures we expect TEST_FAILURES > 0 and GREP_EXIT_STATUS = 0,
-# With no test failures we expect TEST_FAILURES = 0 and GREP_EXIT_STATUS = 1, whereas
-# GREP_EXIT_STATUS > 1 would indicate an error in grep such as failure to find the log file.
 killall $RANDSERV || :
-
-TEST_FAILURES=$(grep -c -- '- FAILED$' ./tests_results/security/localhost.1/output.log) || GREP_EXIT_STATUS=$?
-
-if [ ${GREP_EXIT_STATUS:-0} -eq 1 ]; then
-  echo "okay: test suite detected no failures"
-else
-  if [ ${GREP_EXIT_STATUS:-0} -eq 0 ]; then
-    # while a situation in which grep return status is 0 and it doesn't output
-    # anything shouldn't happen, set the default to something that is
-    # obviously wrong (-1)
-    echo "error: test suite had ${TEST_FAILURES:--1} test failure(s)"
-    exit 1
-  else
-    if [ ${GREP_EXIT_STATUS:-0} -eq 2 ]; then
-      echo "error: grep has not found log file"
-      exit 1
-    else
-      echo "error: grep failed with exit code: ${GREP_EXIT_STATUS}"
-      exit 1
-    fi
-  fi
-fi
-echo "test suite completed"
 %endif
 
 %install
@@ -895,6 +867,9 @@ update-crypto-policies &> /dev/null || :
 
 
 %changelog
+* Fri Feb  8 2019 Daiki Ueno <dueno@redhat.com> - 3.41.0-5
+- Simplify test failure detection in %%check
+
 * Fri Feb 01 2019 Fedora Release Engineering <releng@fedoraproject.org> - 3.41.0-4
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_30_Mass_Rebuild