Fixed vm86_enter race conditions.

diff --git a/include/thread.h b/include/thread.h
index 2107056..5ecfc27 100644
--- a/include/thread.h
+++ b/include/thread.h
@@ -101,11 +101,10 @@
     DWORD        alarms;         /* --3 22c Data for vm86 mode */
     DWORD        vm86_pending;   /* --3 230 Data for vm86 mode */
     void        *vm86_ptr;       /* --3 234 Data for vm86 mode */
-    void        *vm86_ctx;       /* --3 238 Data for vm86 mode */
     /* here is plenty space for wine specific fields (don't forget to change pad6!!) */
 
     /* the following are nt specific fields */
-    DWORD        pad6[623];                  /* --n 23c */
+    DWORD        pad6[624];                  /* --n 238 */
     UNICODE_STRING StaticUnicodeString;      /* -2- bf8 used by advapi32 */
     USHORT       StaticUnicodeBuffer[261];   /* -2- c00 used by advapi32 */
     DWORD        pad7;                       /* --n e0c */