Fix overflow testing in sbrk. am: 1944780b am: 3a5ebf31 -s ours am: d95336ac am: 09933196 am: 0ae30d9a am: 83b0671a am: 10a48fb5 am: fd84d78b * commit 'fd84d78b': Fix overflow testing in sbrk. Change-Id: I8bf29354a9a631ad7c33a1eab3f66124546b7331