revert change to tempdir in SortingCollection introduced in #910 #1030 (

#1031)

* #910 changed the location of temporary files created by SortingCollection, reverting this change since it was causing problems downstream
* fixes #1030

src/main/java/htsjdk/samtools/util/SortingCollection.java

@@ -34,6 +34,7 @@
 import java.lang.reflect.Array;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -344,7 +345,7 @@ public static <T> SortingCollection<T> newInstance(final Class<T> componentType,
                                                        final Comparator<T> comparator,
                                                        final int maxRecordsInRAM) {
 
-        final Path tmpDir = IOUtil.getDefaultTmpDirPath();
+        final Path tmpDir = Paths.get(System.getProperty("java.io.tmpdir"));
         return new SortingCollection<T>(componentType, codec, comparator, maxRecordsInRAM, tmpDir);
     }