fix LHE counting for NLO setups

Some events in FxFx setups have lines like

<event npLO=" -1 " npNLO=" 1 ">

so safer to count eh /event occurrences instead.

cc @ewelina

Generators/EvgenJobTransforms/share/skel.GENtoEVGEN.py

@@ -789,15 +789,15 @@ if hasattr(runArgs, "outputTXTFile"):
     # counting the number of events in LHE output
     count_ev = 0
     with open(eventsFile) as f:
-        for l in f:
-            count_ev += l.count('<event>')
+        lines = f.read()
+        count_ev = lines.count('/event')
     print "MetaData: %s = %s" % ("Number of produced LHE events ", count_ev)
 elif hasattr(runArgs, "inputGeneratorFile"):
     # counting the number of events in LHE output
     count_ev = 0
     with open(eventsFile) as f:
-        for l in f:
-            count_ev += l.count('<event>')
+        lines = f.read()
+        count_ev = lines.count('/event')
     print "MetaData: %s = %s" % ("Number of input LHE events ", count_ev)
 
 if _checkattr("description", required=True):