LU-14291 tests: make module loading of ost optional

LU-14291 tests: make module loading of ost optional

Future Lustre versions will no longer have an ost kernel module.
load_module in the test framework will failure so capture the
failure to ignore it. We will need this for interop testing.

Change-Id: Iedff4f6a36ceffa9428e3f891db78b7538217085
Test-Parameters: trivial
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/54040
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>