[ROCm] fix gpu_conv_algorithm_picker on ROCm build
close it as https://github.com/tensorflow/tensorflow/commit/e9bd1094b7d3c047ff6abbe503e124f253ea29ce has fixed it

Thanks! @cheshire 
This new added PR https://github.com/tensorflow/tensorflow/commit/9b616058967513340d882623c489b25398849373 has broken ROCm build and it is for CUDA only, as ROCm implementation has not used redzone. 

This PR fixes it.

@cheshire Thanks in advance! 