[hmtx/vmtx] Fix a crasher

src/hb-ot-hmtx-table.hh

diff --git a/src/hb-ot-hmtx-table.hh b/src/hb-ot-hmtx-table.hh
index 6073585..1eb6cc6 100644
--- a/src/hb-ot-hmtx-table.hh
+++ b/src/hb-ot-hmtx-table.hh
@@ -255,7 +255,7 @@
       if (glyph < num_advances)
         return table->longMetricZ[glyph].sb;
 
-      if (unlikely (glyph > num_metrics))
+      if (unlikely (glyph >= num_metrics))
         return 0;
 
       const FWORD *bearings = (const FWORD *) &table->longMetricZ[num_advances];