rx: Reorganize LWP rxi_Sendmsg to use 'goto error'
Our LWP version of rxi_Sendmsg can allocate an fd_set, but we don't
free the fd_set if sendmsg() returns certain errors afterwards.
To make sure we go through the same cleanup code for the different
possible error code paths, reorganize the function to go through a
'goto error'-style destructor. This also makes our return codes a bit
more consistent; we should always return -errno now for errors.
Change-Id: I5eaeb7f4ea1d76acc3bd9c52dc258f53f59f631e
Reviewed-on: https://gerrit.openafs.org/14422
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>