verity: short circuit once you hit a verified node

Since we set the VERIFIED bits top-down we can short circuit once
we hit a VERIFIED node.

BUG=9752
TEST=Ran tests in verity.git. Ran platform_DMVerityCorruption on H/W.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
kernel.git Review URL: http://codereview.chromium.org/6670008

TBRing because code has already been LGTMed and committed to kernel.git.

Change-Id: Ib8fe833668a62bdc21946e2b274f970b0955cd8c

TBR=wad@chromium.org,taysom@chromium.org,ups@chromium.org

Review URL: http://codereview.chromium.org/6721017
1 file changed