rand_win.c: fix logical bug in readscreen.

crypto/rand/rand_win.c

diff --git a/crypto/rand/rand_win.c b/crypto/rand/rand_win.c
index 5198351..5d134e1 100644
--- a/crypto/rand/rand_win.c
+++ b/crypto/rand/rand_win.c
@@ -750,7 +750,7 @@
   int		y;		/* y-coordinate of screen lines to grab */
   int		n = 16;		/* number of screen lines to grab at a time */
 
-  if (GetVersion() >= 0x80000000 || !OPENSSL_isservice())
+  if (GetVersion() < 0x80000000 && OPENSSL_isservice()>0)
     return;
 
   /* Create a screen DC and a memory DC compatible to screen DC */