Unix CM: Catch ICL initialisation failures

If afs_icl_CreateLog fails, don't still call afS_icl_CreateSet.
If afs_icl_CreateSetWithFlags fails, don't ignore its error code.

Caught by clang-analyzer

Change-Id: I245f4391bbbf183492e8c13fb8f091b339cea80a
Reviewed-on: http://gerrit.openafs.org/9203
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>