LU-6142 echo: SPDX for OBD Echo

LU-6142 echo: SPDX for OBD Echo

Convert from verbose license text to SPDX.

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I7a7a55638eb32e605257fc4954eadfc8d84ae00d
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/57795
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>