Allow work dir to be deleted on Windows.

SVN-Revision: 1272
diff --git a/libarchive/test/main.c b/libarchive/test/main.c
index 830b6a9..d478bf7 100644
--- a/libarchive/test/main.c
+++ b/libarchive/test/main.c
@@ -1212,6 +1212,7 @@
 
 	/* If the final tmpdir is empty, we can remove it. */
 	/* This should be the usual case when all tests succeed. */
+	chdir("..");
 	rmdir(tmpdir);
 
 	return (tests_failed);