Skip creation of existing files when mounting from the host
This change skips the creation of a file if it already exists. This may be the case, for example, if the folder containing the file on the host is mounted as part of the docker command line.
See for example:
- https://github.com/NVIDIA/nvidia-docker/issues/1690
- https://github.com/NVIDIA/libnvidia-container/issues/187
Signed-off-by: Evan Lezar elezar@nvidia.com