dev-amdgpu: Hotfix variable initialization

These non-initialized variables were causing the trace reader not to
record all lines.

Change-Id: I88764493d8124c072bc90ff9c08aa26421467f7b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53063
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed