Update 81 LUN Paths Check.ps1

Edited -ge to -lt. Previously proposed fix inverted answer. $lun is precented in report if being less than the recommended number. In default means if there is less than 2 paths then it is an error. 2 or more is good.
Merge pull request #59 from jones-g/patch-2

Update 81 LUN Paths Check.ps1