pgsql: Try and silence spurious Coverity warning.

Try and silence spurious Coverity warning.

gset_data (aka gd) in planner.c is always non-null if and only if
parse->groupingSets is non-null, but Coverity doesn't know that and
complains.  Feed it an assertion to see if that keeps it happy.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/f5780935266bd72951c770396f9267366414d1b9

Modified Files
--------------
src/backend/optimizer/plan/planner.c | 2 ++
1 file changed, 2 insertions(+)