Fixed documentation error
Fixed documentation error

ninghang/opencvmex,fengzhyuan/mexopencv,bearpaw/mexopencv,nanit/mexopencv,CVML/mexopencv,nanit/mexopencv,bearpaw/mexopencv,CVML/mexopencv,fengzhyuan/mexopencv,ninghang/opencvmex