LU-18016 kfilnd: avoid wrong call to kfilnd_ep_put_key

LU-18016 kfilnd: avoid wrong call to kfilnd_ep_put_key

kfilnd_tn_alloc(): do not call kfilnd_ep_put_key() if
kfilnd_ep_get_key() was not called

HPE-bug-id: LUS-12405
Test-Parameters: trivial
Signed-off-by: Vladimir Saveliev <vladimir.saveliev@hpe.com>
Change-Id: I6dc9f581b5632a9a220cc04f4b5735581b75f40a
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55688
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>