afs: Avoid -1 error for vreadUIO/vwriteUIO
Commit
c6b61a45 (afs: Verify osi_UFSOpen worked) added various checks
to return an error if a given osi_UFSOpen failed. However, two of
these checks (in afs_UFSReadUIO and afs_UFSWriteUIO) result in us
returning -1 on error, in functions that otherwise return errno codes
(e.g. ENOSPC). An error code of -1 might get interpreted as
RX_CALL_DEAD, which would be rather confusing, so use EIO as a generic
error instead.
Change-Id: I23b9a73b82d999d8ee4670b5e7ec39b9d820fb0f
Reviewed-on: https://gerrit.openafs.org/13931
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>