ws2_32: Explicitly ignore the output buffer in FIONBIO.

dlls/ws2_32/socket.c

@@ -3368,8 +3368,10 @@ INT WINAPI WSAIoctl(SOCKET s, DWORD code, LPVOID in_buff, DWORD in_size, LPVOID
             return -1;
         }
 
+        /* Explicitly ignore the output buffer; WeChat tries to pass an address
+         * without write access. */
         ret = server_ioctl_sock( s, IOCTL_AFD_WINE_FIONBIO, in_buff, in_size,
-                                 out_buff, out_size, ret_size, overlapped, completion );
+                                 NULL, 0, ret_size, overlapped, completion );
         SetLastError( ret );
         return ret ? -1 : 0;
     }

dlls/ws2_32/tests/sock.c

@@ -3934,7 +3934,7 @@ static void test_fionbio(void)
 
     output = VirtualAlloc(NULL, 4, MEM_RESERVE | MEM_COMMIT, PAGE_NOACCESS);
     ret = WSAIoctl(s, FIONBIO, &one, sizeof(one) + 1, output, 4, &size, NULL, NULL);
-    todo_wine ok(!ret, "got error %u\n", WSAGetLastError());
+    ok(!ret, "got error %u\n", WSAGetLastError());
     VirtualFree(output, 0, MEM_FREE);
 
     overlapped.Internal = 0xdeadbeef;