intel/aub_viewer: silence compiler warning

buffer_addr may be used uninitialized.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>

src/intel/tools/aubinator_viewer_decoder.cpp

@@ -364,7 +364,7 @@ handle_3dstate_vertex_buffers(struct aub_viewer_decode_ctx *ctx,
       if (iter.struct_desc != vbs)
          continue;
 
-      uint64_t buffer_addr;
+      uint64_t buffer_addr = 0;
 
       struct gen_field_iterator vbs_iter;
       gen_field_iterator_init(&vbs_iter, vbs, &iter.p[iter.start_bit / 32], 0, false);