Use a less hacky way to detect if a module is Fuzzer enabled

Bug: 169004486
Test: presubmit
Change-Id: I7fad86041622979b9befb7c86897a13f604bdf3d
diff --git a/cc/lto.go b/cc/lto.go
index a8bed23..8d6e3e7 100644
--- a/cc/lto.go
+++ b/cc/lto.go
@@ -74,7 +74,7 @@
 func (lto *lto) flags(ctx BaseModuleContext, flags Flags) Flags {
 	// TODO(b/131771163): Disable LTO when using explicit fuzzing configurations.
 	// LTO breaks fuzzer builds.
-	if inList("-fsanitize=fuzzer-no-link", flags.Local.CFlags) {
+	if ctx.isFuzzer() {
 		return flags
 	}