Windows: Fix use of file descriptors as sockets

Sockets and file descriptors are not interchangeable on Windows.  The
test for checking whether a given value is a socket or an FD was
broken for the case where WinSock was not initialized to begin with.

lib/roken/net_read.c

@@ -86,7 +86,8 @@ net_read(rk_socket_t sock, void *buf, size_t nbytes)
 
 	if (use_read == 0 &&
 	    rk_IS_SOCKET_ERROR(count) &&
-	    rk_SOCK_ERRNO == WSAENOTSOCK) {
+            (rk_SOCK_ERRNO == WSANOTINITIALISED ||
+             rk_SOCK_ERRNO == WSAENOTSOCK)) {
 	    use_read = 1;
 
 	    count = _read (sock, cbuf, rem);

lib/roken/net_write.c

@@ -83,7 +83,8 @@ net_write(rk_socket_t sock, const void *buf, size_t nbytes)
 
 	if (use_write == 0 &&
 	    rk_IS_SOCKET_ERROR(count) &&
-	    rk_SOCK_ERRNO == WSAENOTSOCK) {
+	    (rk_SOCK_ERRNO == WSANOTINITIALISED ||
+             rk_SOCK_ERRNO == WSAENOTSOCK)) {
 	    use_write = 1;
 
 	    count = _write (sock, cbuf, rem);