[libFuzzer] Properly check if we can use dumpbin.

The flag "/sumary" is necessary, otherwise it returns a non-zero value.

Differential Revision: https://reviews.llvm.org/D29371

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293790 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed