pgsql: Close socket in case of errors in setting non-blocking

Close socket in case of errors in setting non-blocking

If configuring the newly created socket non-blocking fails we
error out and return INVALID_SOCKET, but the socket that had
been created wasn't closed. Fix by issuing closesocket in the
errorpath.

Backpatch to all supported branches.

Author: Ranier Vilela <ranier.vf@gmail.com>
Discussion: https://postgr.es/m/CAEudQApmU5CrKefH85VbNYE2y8H=-qqEJbg6RAPU65+vCe+89A@mail.gmail.com
Backpatch-through: v12

Branch
------
REL_16_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/6614d38d8780670d2337090bdf2ec81c0b8bab8e

Modified Files
--------------
src/backend/port/win32/socket.c | 1 +
1 file changed, 1 insertion(+)