complex.c: no overflow
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60041 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
complex.c: no overflow
unnecessary multiplication.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60041 b2dd03c8-39d4-4d8f-98ff-823fe69b080e