vm_memory: Format GuestAddress in hex for Debug.
vm_memory: Format GuestAddress in hex for Debug.

This is generally more useful when it shows up in log messages.

BUG=b:244553205
TEST=tools/dev_container tools/run_tests

Change-Id: Idbaa58f7a9fdb8e69212074fb5853da9098a82fb
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/3921603
Reviewed-by: Alexandre Courbot <301cd6a3ea50a894b4b51e385c5eb12b9a4ffc0c@chromium.org>
Commit-Queue: Andrew Walbran <91a7c1b7f9f624e0ed1b099dc85ecb6025941ee9@google.com>

google/crosvm,google/crosvm,google/crosvm,google/crosvm