LU-6142 libcfs: checkpatch cleanup of libcfs fail.c

Resolve several checkpatch issues reported for fail.c. This brings
us into aligment with the native Linux client version.

Test-Parameters: trivial
Change-Id: I71e71f48a94fa20756f7696b5fbf115c919d05d3
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/44207
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>