Fix typo in r19923 (bounds check offset propagation)

src/hydrogen-bce.cc

Index: src/hydrogen-bce.cc
diff --git a/src/hydrogen-bce.cc b/src/hydrogen-bce.cc
index cef1e0fca0b5974d9848ae64d8faaf111c31c885..c98a03cb5ab32d78b79a214c07edf5ecd2b1ee97 100644
--- a/src/hydrogen-bce.cc
+++ b/src/hydrogen-bce.cc
@@ -183,7 +183,7 @@ class BoundsCheckBbData: public ZoneObject {
         lower_check_ = new_check;
       } else {
         TightenCheck(lower_check_, new_check);
-        UpdateLowerOffsets(upper_check_, upper_offset_);
+        UpdateLowerOffsets(lower_check_, lower_offset_);
       }
     } else {
       // Should never have called CoverCheck() in this case.