Log the correct error when the rootfs hash/size mismatches on deltas.

BUG=None
TEST=Unittests

Change-Id: If2ca1eecaacfa23deedc08b52a4f8033e4d0359c
Reviewed-on: https://gerrit.chromium.org/gerrit/46906
Tested-by: Chris Sosa <sosa@chromium.org>
Reviewed-by: Chris Masone <cmasone@chromium.org>
Reviewed-by: Jay Srinivasan <jaysri@chromium.org>
Commit-Queue: Chris Sosa <sosa@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
diff --git a/delta_performer.cc b/delta_performer.cc
index b0c8c17..74e21e2 100644
--- a/delta_performer.cc
+++ b/delta_performer.cc
@@ -1089,8 +1089,8 @@
                install_plan_->rootfs_hash.size()) == 0;
     if (!valid) {
       LogVerifyError(false,
-                     StringForHashBytes(install_plan_->kernel_hash.data(),
-                                        install_plan_->kernel_hash.size()),
+                     StringForHashBytes(install_plan_->rootfs_hash.data(),
+                                        install_plan_->rootfs_hash.size()),
                      StringForHashBytes(info.hash().data(),
                                         info.hash().size()));
     }