Fix overflow testing in sbrk. am: 1944780b am: 3a5ebf31 -s ours am: d95336ac am: 09933196 am: 0ae30d9a am: 83b0671a am: 10a48fb5 am: fd84d78b am: b4d92e13 am: ad80daaa * commit 'ad80daaa': Fix overflow testing in sbrk. Change-Id: Iacf234b6d224df38dc59fde9c3c9f8a82ba1ad0a