[moblab] Tidy up the boot logging.

There was a extra -e in the logging removed
Test to see if the log directory exists
make this a task
add some tabs and improve the output format
add in a datetime column - can be used later for optimizations

TEST=localally tested on moblab

Change-Id: I2044de03585c135314f639d2c2b58dc0aed1d93d
Reviewed-on: https://chromium-review.googlesource.com/1541642
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Keith Haddow <haddowk@chromium.org>
Reviewed-by: Matt Mallett <mattmallett@chromium.org>
1 file changed