Apply fixes from clag-tidy misc-unused-parameters

Summary: Gets the project clean of `-Wunused-parameter`, part of `-Wextra`. Enforced as part of the build now.

Differential Revision: https://internalfb.com/D45772554

fbshipit-source-id: e7ec6f4047b3994c3615a4557ffc4f3677f9c1e6

tests/YGLoggerTest.cpp

@@ -14,9 +14,9 @@
 namespace {
 char writeBuffer[4096];
 int _unmanagedLogger(
-    const YGConfigRef config,
-    const YGNodeRef node,
-    YGLogLevel level,
+    const YGConfigRef /*config*/,
+    const YGNodeRef /*node*/,
+    YGLogLevel /*level*/,
     const char* format,
     va_list args) {
   return vsnprintf(