Fix un-initialized error introduced by r291959.

This is uncovered when running tools/dsymutil/X86/empty_range.s.test
with ASAN. Haven't investigate yet, whether that means there is an ODR
violation in that test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292065 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed