LU-6142 lnet: update files with correct SPDX

LU-6142 lnet: update files with correct SPDX

Some files were given LGPL-2.0 when they should have been
LGPL-2.1 based on the previous license text. Add the Linux
syscall note to UAPI headers.

Add SPDX to a few missed files in LNET.

Fixes: 0f39311369 ("LU-6142 lnet: SPDX for lnet/utils/")
Fixes: c9a7728476 ("LU-6142 lnet: SPDX for lnet/include/ and misc files")
Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I6ceadfa182909ed4e3e52f88b4d37249cb30b6ef
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55930
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: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>