generic/131: Save stderr for debugging
Details of which internal step failed within a test are lost without
additional debugging output. Save that output by separating stdout and
stderr.
This allows the server port to be written solely to stdout for
consumption by the script. Then all error output can be sent to the
seqres.full file in the event of a failure. Then, depend on the return
code of the server _and_ the client to detect failure and save the error
output for inspection.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>