[lavapipe] Conditionalize logging/tracing around USE_MAGMA.

Change-Id: I3c0c1f0411af641cd9097785ebe716a6d6d194a1
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/mesa/+/1015476
Reviewed-by: Josh Gargus <jjosh@google.com>
Commit-Queue: John Rosasco <rosasco@google.com>
5 files changed