Fix harmless warnings with mingw in timing.c
diff --git a/library/timing.c b/library/timing.c
index a612208..913cbdc 100644
--- a/library/timing.c
+++ b/library/timing.c
@@ -251,9 +251,13 @@
     return( delta );
 }
 
-DWORD WINAPI TimerProc( LPVOID uElapse )
+/* It's OK to use a global because alarm() is supposed to be global anyway */
+static DWORD alarmMs;
+
+DWORD WINAPI TimerProc( LPVOID TimerContext )
 {
-    Sleep( (DWORD) uElapse );
+    ((void) TimerContext);
+    Sleep( alarmMs );
     alarmed = 1;
     return( TRUE );
 }
@@ -263,8 +267,8 @@
     DWORD ThreadId;
 
     alarmed = 0;
-    CloseHandle( CreateThread( NULL, 0, TimerProc,
-        (LPVOID) ( seconds * 1000 ), 0, &ThreadId ) );
+    alarmMs = seconds * 1000;
+    CloseHandle( CreateThread( NULL, 0, TimerProc, NULL, 0, &ThreadId ) );
 }
 
 void m_sleep( int milliseconds )