fixed typo in transform_iterator documentation resolves issue #136
fixed typo in transform_iterator documentation
resolves issue #136

Reported by David Coerjolly

xiongzhanblake/thrust_src,sarvex/thrust,mohamed-ali/thrust,raygit/thrust,Ricardo666666/thrust,dachziegel/thrust,mohamed-ali/thrust,zhenglaizhang/thrust,GrimDerp/thrust,marksantos/thrust,dachziegel/thrust,andrewcorrigan/thrust-multi-permutation-iterator,GrimDerp/thrust,andrewcorrigan/thrust-multi-permutation-iterator,xiongzhanblake/thrust,jaredhoberock/thrust,raygit/thrust,arnabgho/thrust,thrust/thrust,thrust/thrust,zhenglaizhang/thrust,egaburov/thrust,sdalton1/thrust,jaredhoberock/thrust,andrewcorrigan/thrust-multi-permutation-iterator,arnabgho/thrust,thvasilo/thrust,thvasilo/thrust,marksantos/thrust,zeryx/thrust,GrimDerp/thrust,sdalton1/thrust,Ricardo666666/thrust,jaredhoberock/thrust,zhenglaizhang/thrust,egaburov/thrust,sarvex/thrust,thrust/thrust,egaburov/thrust,sdalton1/thrust,xiongzhanblake/thrust,raygit/thrust,jaredhoberock/thrust,arnabgho/thrust,thrust/thrust,mohamed-ali/thrust,Ricardo666666/thrust,xiongzhanblake/thrust_src,thvasilo/thrust,marksantos/thrust,sarvex/thrust,jaredhoberock/thrust,zeryx/thrust,dachziegel/thrust,xiongzhanblake/thrust_src,thrust/thrust,zeryx/thrust,xiongzhanblake/thrust