Wayland: use 'use_fuzzing_engine_with_lpm'

In the future, multiple fuzzing engines (beyond libfuzzer) will support
libprotobuf-mutator, so we're moving to a more generic gn variable.

Bug: 1369919
Change-Id: Ia599996b7dc255623b56963cae5fc13447cc0ad7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4293094
Commit-Queue: Adrian Taylor <adetaylor@chromium.org>
Reviewed-by: Nic Hollingum <hollingum@google.com>
Cr-Commit-Position: refs/heads/main@{#1116274}

components/exo/wayland/fuzzer/BUILD.gn

@@ -76,7 +76,7 @@ wayland_templater("corpus") {
   script_override = "wayland_sequencer.py"
 }
 
-if (use_libfuzzer) {
+if (use_fuzzing_engine_with_lpm) {
   fuzzer_test("wayland_fuzzer") {
     sources = [ "fuzzer.cc" ]