scudo: Work around gcc 8 conversion warning.

Should fix:
https://lab.llvm.org/buildbot#builders/99/builds/2953

GitOrigin-RevId: f2819ee6cc46c89d049e8dca205c269e7c40cdc2
Change-Id: If518ce8b5bcab30d7d5c51f320bbaf5101e6727b
1 file changed