LU-6142 lnet: return proper error code

LU-6142 lnet: return proper error code

It is consider bad style in the linux kernel to
return -1 or a positive number for an error.
Instead return the appropriate error codes.

Change-Id: Icd9729de84f162b07df17caab48e7693459a03e8
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: http://review.whamcloud.com/17626
Tested-by: Jenkins
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>