cshored: rootfs-postprocess: Clean /run
cshored: rootfs-postprocess: Clean /run

/run is not persistent in CShoreED, and is a mountpoint, so
clear files from this directory in rootfs post-processing.

Signed-off-by: Daniel Dickinson <8387375b7066459d9b5dcfebff567b1a650a8a0a@cshore.thecshore.com>

cshoredaniel/meta-cshored,cshoredaniel/meta-cshored,cshoredaniel/meta-cshored