[asan] initialze varaibles to avoid a (false positive) report from gcc's -Wmaybe-uninitialized

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211008 91177308-0d34-0410-b5e6-96231b3b80d8
Add Guan-Hong Liu.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@211009 91177308-0d34-0410-b5e6-96231b3b80d8