prism-auto fix: when checking output files in test mode, fail immediately when the first one is different.

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@11983 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/etc/scripts/prism-auto

@@ -471,6 +471,8 @@ def verifyAndCleanupExports(outFiles, exportPrefix):
                 msg = msg + "FAIL (no " + os.path.basename(expFile) + " to compare to)"
                 result = False
     	printTestResult(msg)
+    	if not result:
+    		return result
     return result
 
 # Run a benchmark, specified by a list of command-line args,