LU-8602 gss: autoconf check missing "test" keyword

LU-8602 gss: autoconf check missing "test" keyword

Change https://review.whamcloud.com/31095 introduced an error in the
autoconf, omitting the command "test" in an autoconf check.  Add it.

Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Change-Id: I525805801d9e8166ec1064dccbf6cec6f97efdfa
Reviewed-on: https://review.whamcloud.com/31191
Reviewed-by: Jeremy Filizetti <jeremy.filizetti@gmail.com>
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>