Fix typo in Of variance and functors post
Fix typo in Of variance and functors post

typelevel/typelevel.github.com,melrief/typelevel.github.com,S11001001/typelevel.github.com,melrief/typelevel.github.com,S11001001/typelevel.github.com,melrief/typelevel.github.com,S11001001/typelevel.github.com,typelevel/typelevel.github.com,S11001001/typelevel.github.com,typelevel/typelevel.github.com,melrief/typelevel.github.com