LU-17795 lnet: unused return code in lnet_peer_data_present

LU-17795 lnet: unused return code in lnet_peer_data_present

Coverity check detected an issue with the return code from the call to
lnet_peer_set_primary_nid() in the code added by LU-17379 patch.
Fix it.

Test-Parameters: trivial testlist=sanity-lnet
Fixes: ae6d37 ("LU-17379 lnet: parallelize peer discovery via LNetAddPeer")
Signed-off-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Change-Id: I8b9df330200ff2732efd2a54d8de910463993fae
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/54971
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>