LU-17000 gss: update init_channel initialization

LU-17000 gss: update init_channel initialization

Update 'init_channel' to match newer coding guidelines.

DDN-Bug-Id: EX-9705
Test-Parameters: trivial
Test-Parameters: testgroup=review-dne-selinux-ssk-part-2
Test-Parameters: testgroup=review-dne-part-2
Test-Parameters: kerberos=true testlist=sanity-krb5
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I6539ade1a9d815664f6659a5c1ee25e7f1f7df0e
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55322
Reviewed-by: Yang Sheng <ys@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>