update_engine: Fix TPM variable name max_kernel_rollfoward

- In a previous CL I named the variable incorrectly

BUG=chromium:814090
TEST=FEATURES=test emerge-samus update_engine

Change-Id: I17cbc85d42ba03040bfdae436cedd0238698b47e
Reviewed-on: https://chromium-review.googlesource.com/1059944
Commit-Ready: Zentaro Kavanagh <zentaro@chromium.org>
Tested-by: Zentaro Kavanagh <zentaro@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/common/mock_hardware.h b/common/mock_hardware.h
index fcbb0d5..662ccd9 100644
--- a/common/mock_hardware.h
+++ b/common/mock_hardware.h
@@ -93,7 +93,7 @@
   MOCK_CONST_METHOD0(GetMinKernelKeyVersion, int());
   MOCK_CONST_METHOD0(GetMinFirmwareKeyVersion, int());
   MOCK_CONST_METHOD1(SetMaxKernelKeyRollforward,
-                     bool(int max_kernel_rollforward));
+                     bool(int kernel_max_rollforward));
   MOCK_CONST_METHOD0(GetPowerwashCount, int());
   MOCK_CONST_METHOD1(GetNonVolatileDirectory, bool(base::FilePath*));
   MOCK_CONST_METHOD1(GetPowerwashSafeDirectory, bool(base::FilePath*));