LU-17483 gss: refresh req context with already existing one

LU-17483 gss: refresh req context with already existing one

When we are processing a request with a root GSS context that
has the PTLRPC_CTX_ERROR_BIT bit set, try to replace it with an
already existing context. Such a context can already be up-to-date
thanks to other authentication requests sent to failover NIDs while
the current request was in the delay list. This valid context can be
fetched from the struct ptlrpc_sec.

Lustre-change: https://review.whamcloud.com/53859
Lustre-commit: c76f7288fa772b48cf81050663e2124b25ab3994

Test-Parameters: kerberos=true testlist=sanity-krb5
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: Iff1cf727c4579cba6456e010aac6537cf888b0ae
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/55169
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>