src: avoid strcmp in ImportJWKAsymmetricKey

Do not unnecessarily resolve the Utf8Value into a const char* just to
then use strcmp. Instead, just take a reference to the Utf8Value and use
its operator==.

src/crypto/crypto_keys.cc

@@ -511,16 +511,16 @@ Maybe<bool> ExportJWKAsymmetricKey(
 std::shared_ptr<KeyObjectData> ImportJWKAsymmetricKey(
     Environment* env,
     Local<Object> jwk,
-    const char* kty,
+    const Utf8Value& kty,
     const FunctionCallbackInfo<Value>& args,
     unsigned int offset) {
-  if (strcmp(kty, "RSA") == 0) {
+  if (kty == "RSA") {
     return ImportJWKRsaKey(env, jwk, args, offset);
-  } else if (strcmp(kty, "EC") == 0) {
+  } else if (kty == "EC") {
     return ImportJWKEcKey(env, jwk, args, offset);
   }
 
-  THROW_ERR_CRYPTO_INVALID_JWK(env, "%s is not a supported JWK key type", kty);
+  THROW_ERR_CRYPTO_INVALID_JWK(env, "%s is not a supported JWK key type", *kty);
   return std::shared_ptr<KeyObjectData>();
 }
 
@@ -1040,7 +1040,7 @@ void KeyObjectHandle::InitJWK(const FunctionCallbackInfo<Value>& args) {
       return;
     }
   } else {
-    key->data_ = ImportJWKAsymmetricKey(env, input, *kty_string, args, 1);
+    key->data_ = ImportJWKAsymmetricKey(env, input, kty_string, args, 1);
     if (!key->data_) {
       // ImportJWKAsymmetricKey is responsible for throwing an appropriate error
       return;