LFSPointerTest: suppress errorprone error [SelfComparison]

The test #testCompareToSame tests comparing against self intentionally.
Suppress the error raised by errorprone.

Change-Id: If8d70a51ab34ffb6d7f0c9d409746aee8b031408
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LFSPointerTest.java

@@ -241,6 +241,7 @@ public class LFSPointerTest {
 	}
 
 	@Test
+	@SuppressWarnings("SelfComparison")
 	public void testCompareToSame() throws Exception {
 		AnyLongObjectId id = LongObjectId.fromString(TEST_SHA256);
 		LfsPointer lfs = new LfsPointer(id, 4);