Also check for closesocket in winsock2.h

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@10086 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

configure

@@ -1630,7 +1630,8 @@ check_func getrusage
 check_func2 windows.h GetProcessTimes
 
 check_func fork
-check_func closesocket
+check_func closesocket ||
+    check_func2 winsock2.h closesocket
 
 test "$vhook" = "default" && vhook="$dlopen"