[asan] fix the bug with memalign and malloc_usable_size (http://code.google.com/p/address-sanitizer/issues/detail?id=193); also fix lint

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@183647 91177308-0d34-0410-b5e6-96231b3b80d8