LU-15509 lnet: Ping buffer ref leak in lnet_peer_data_present

LU-15509 lnet: Ping buffer ref leak in lnet_peer_data_present

lnet_peer_merge_data() and lnet_peer_set_primary_data() are
responsible for dropping the reference on the ping buffer that is
taken by lnet_peer_push_event() and lnet_discovery_event_reply().
However, there are some error paths in lnet_peer_data_present()
where we do not call either lnet_peer_merge_data() or
lnet_peer_set_primary_data(). In these cases, we need to drop
the reference on the ping buffer otherwise it will leak.

HPE-bug-id: LUS-10715
Test-Parameters: trivial testlist=sanity-lnet
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: I36ba0017caa9d6ce139f94090912496f14eda626
Reviewed-on: https://review.whamcloud.com/46431
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andriy Skulysh <andriy.skulysh@hpe.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>