LINUX: Allocate error queue buffer once

LINUX: Allocate error queue buffer once

We call osi_HandleSocketError in a loop, so make sure we process all
of the errors. We were allocating a buffer to process the errors in
osi_HandleSocketError itself, but we can reuse the same buffer on
subsequent invocations, to reduce allocation/free pressure if we need
to call osi_HandleSocketError more than once. So, do that.

Change-Id: Idca2b9d21a48a868574ce6cfc5efe2efba3570a1
Reviewed-on: http://gerrit.openafs.org/8115
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>