wasted work in Lucene40TermVectorsWriter.finishTerm()

The problem appears in version 4.3.0 and in revision 1490286. I
attached a two-line patch that fixes it.

In method "Lucene40TermVectorsWriter.finishTerm", the loop over
"offsetStartBuffer" should not be executed when "offsets" is "false".
When "offsets" is "false" the loop produces no results. The patch
just flips the order of the "if" and "for" statements.

Method "collect" in class "MultiComparatorNonScoringCollector" has a
similar loop (the last loop in the method over "comparators"), and
this loop is not executed when "queueFull" is false, just like in the
proposed patch.