Fix failing max map count check test

This commit fixes failing max map count check test due to the use of a
logging message supplier.

core/src/test/java/org/elasticsearch/bootstrap/MaxMapCountCheckTests.java

@@ -26,6 +26,8 @@ import org.apache.lucene.util.Constants;
 import org.elasticsearch.common.SuppressLoggerChecks;
 import org.elasticsearch.common.io.PathUtils;
 import org.elasticsearch.test.ESTestCase;
+import org.hamcrest.Matcher;
+import org.mockito.ArgumentMatcher;
 
 import java.io.BufferedReader;
 import java.io.IOException;
@@ -34,6 +36,7 @@ import java.nio.file.Path;
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.argThat;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.reset;
@@ -71,21 +74,28 @@ public class MaxMapCountCheckTests extends ESTestCase {
         when(reader.readLine()).thenThrow(ioException);
         final Logger logger = mock(Logger.class);
         assertThat(check.getMaxMapCount(logger), equalTo(-1L));
-        verify(logger).warn(
-            (Supplier<?>) () -> new ParameterizedMessage(
-                "I/O exception while trying to read [{}]", procSysVmMaxMapCountPath), ioException);
+        verify(logger).warn(argThat(argumentMatcher("I/O exception while trying to read [/proc/sys/vm/max_map_count]")), eq(ioException));
         verify(reader).close();
 
         reset(reader);
         reset(logger);
         when(reader.readLine()).thenReturn("eof");
         assertThat(check.getMaxMapCount(logger), equalTo(-1L));
-        verify(logger).warn(eq(
-            (Supplier<?>) () -> new ParameterizedMessage(
-                "unable to parse vm.max_map_count [{}]", "eof")), any(NumberFormatException.class));
+        verify(logger).warn(argThat(argumentMatcher("unable to parse vm.max_map_count [eof]")), any(NumberFormatException.class));
         verify(reader).close();
     }
 
+    private ArgumentMatcher<Supplier<?>> argumentMatcher(final String message) {
+        return new ArgumentMatcher<Supplier<?>>() {
+            @Override
+            public boolean matches(Object o) {
+                final Supplier<?> supplier = (Supplier<?>)o;
+                final ParameterizedMessage parameterizedMessage = (ParameterizedMessage) supplier.get();
+                return parameterizedMessage.getFormattedMessage().equals(message);
+            }
+        };
+    }
+
     public void testMaxMapCountCheckRead() throws IOException {
         final String rawProcSysVmMaxMapCount = Long.toString(randomIntBetween(1, Integer.MAX_VALUE));
         final BufferedReader reader = mock(BufferedReader.class);