r600: fix off-by-one in egd_tables.py

Port of the corresponding fix in sid_tables.py.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/gallium/drivers/r600/egd_tables.py

@@ -110,7 +110,7 @@ class IntTable:
         [static] const typename name[] = { ... };
         to filp.
         """
-        idxs = sorted(self.idxs) + [-1]
+        idxs = sorted(self.idxs) + [len(self.table)]
 
         fragments = [
             ('\t/* %s */ %s' % (