math.c (ruby_lgamma_r): reduce duplicate code
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58645 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
math.c (ruby_lgamma_r): reduce duplicate code
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58645 b2dd03c8-39d4-4d8f-98ff-823fe69b080e