LU-12678 ptlrpc: remove bogus LASSERT

LU-12678 ptlrpc: remove bogus LASSERT

In the error case, it isn't possible for rc to be both -ENOMEM and
0 at the same time, so remove the incorrect LASSERT(rc == 0) to
avoid crashing the system on an allocation failure.

Improve error messages to conform to code style.

Fixes: ceeeae4271fd ("LU-12678 lnet: me: discard struct lnet_handle_me")
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I61ac5d735d7b2658dae76213a2d40cbfd2bb8bb9
Reviewed-on: https://review.whamcloud.com/45421
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>