Fixed some handle type mismatches and added a few casts in prevision
of void* handles.

diff --git a/scheduler/syslevel.c b/scheduler/syslevel.c
index 9d87553..feb3a9b 100644
--- a/scheduler/syslevel.c
+++ b/scheduler/syslevel.c
@@ -148,7 +148,7 @@
  */
 DWORD WINAPI _ConfirmSysLevel(SYSLEVEL *lock)
 {
-    if ( lock && lock->crst.OwningThread == GetCurrentThreadId() )
+    if ( lock && lock->crst.OwningThread == (HANDLE)GetCurrentThreadId() )
         return lock->crst.RecursionCount;
     else
         return 0L;
@@ -160,7 +160,8 @@
  */
 VOID WINAPI _CheckNotSysLevel(SYSLEVEL *lock)
 {
-    if (lock && lock->crst.OwningThread == GetCurrentThreadId() && lock->crst.RecursionCount)
+    if (lock && lock->crst.OwningThread == (HANDLE)GetCurrentThreadId() &&
+        lock->crst.RecursionCount)
     {
         ERR( "Holding lock %p level %d\n", lock, lock->level );
         DbgBreakPoint();