[Sanitizer] fix errors in scanf interceptors: add support for %c and fix cases like %5d

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@173440 91177308-0d34-0410-b5e6-96231b3b80d8
[sanitizer] fix calloc overflow in asan/tsan/msan

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@173441 91177308-0d34-0410-b5e6-96231b3b80d8