store ctest result to prevent it from being overwritten

tests/run_tests.sh

@@ -13,6 +13,7 @@ CTEST_BINARY=/opt/local/bin/ctest
 fi
 
 $CTEST_BINARY -D ExperimentalTest --no-compress-output
+ERRORLEVEL=$?
 cp Testing/`head -n 1 Testing/TAG`/Test.xml CTestResults.xml
 
-exit $?
\ No newline at end of file
+exit $ERRORLEVEL
\ No newline at end of file