LU-11309 lnd: Clean up logging

LU-11309 lnd: Clean up logging

No need to output error in ksocknal_tx_done() as this error is
tracked in lnet.
No need to keep a cookie in the connection. It's always set to
the message. This will allow us to set the msg's health status
properly before calling lnet_finalize()

Test-Parameters: trivial
Signed-off-by: Amir Shehata <ashehata@whamcloud.com>
Change-Id: I168c8ca32192ba4f8f4480e8e7384d45f0a062a7
Reviewed-on: https://review.whamcloud.com/33096
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Doug Oucharek <dougso@me.com>
Reviewed-by: Sonia Sharma <sharmaso@whamcloud.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>