ShowPackDelta: Refactor to use try-with-resource

Remove the resource warning suppression and refactor the code to open
the TemporaryBuffer and InflaterInputStream in a try-with-resource.

Change-Id: I3082e5ac7565c5000d5a4364f750dd0a0952fc6e
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/debug/ShowPackDelta.java

@@ -125,12 +125,13 @@ class ShowPackDelta extends TextBuiltin {
 			ptr++;
 		ptr++;
 
-		@SuppressWarnings("resource" /* java 7 */)
-		TemporaryBuffer.Heap raw = new TemporaryBuffer.Heap(bufArray.length);
+		try (TemporaryBuffer.Heap raw = new TemporaryBuffer.Heap(
+				bufArray.length);
 				InflaterInputStream inf = new InflaterInputStream(
-				new ByteArrayInputStream(bufArray, ptr, bufArray.length));
+						new ByteArrayInputStream(bufArray, ptr,
+								bufArray.length))) {
 			raw.copy(inf);
-		inf.close();
 			return raw.toByteArray();
 		}
+	}
 }