[ubsan] Make the cast overflow message less redundant

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@301589 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 33780624aebb9e414150ca504b734742552e6f7a)
3 files changed