ws2_32/tests: Initialize address length argument before calling recvfrom()/WSARecvFrom() (Coverity).

Signed-off-by: Nikolay Sivov <nsivov@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
diff --git a/dlls/ws2_32/tests/sock.c b/dlls/ws2_32/tests/sock.c
index 91305f9..137c0f6 100644
--- a/dlls/ws2_32/tests/sock.c
+++ b/dlls/ws2_32/tests/sock.c
@@ -6862,7 +6862,7 @@
 {
     struct write_watch_thread_args *args = arg;
     struct sockaddr addr;
-    int addr_len, ret;
+    int addr_len = sizeof(addr), ret;
     DWORD bytes, flags = 0;
     WSABUF buf[1];