Fix 071-dexfile by having run-test use a unique directory

If userdata.img is flashed, the /data/art-test is owned by the system
user.  However, 071 requires the directory it runs in to have be owned
by the running user (root in eng builds).

Change-Id: I5230908291fd2ff6c5ebda98cfc3ef4c7ea7482e
diff --git a/test/071-dexfile/info.txt b/test/071-dexfile/info.txt
index 7328d71..d58cc86 100644
--- a/test/071-dexfile/info.txt
+++ b/test/071-dexfile/info.txt
@@ -1,4 +1,4 @@
 Exercise some Dalvik-specific DEX file features.  This is not expected to
 work on other VMs.
 
-NOTE: the test requires that /data/art-test/ exists and is writable and not mounted noexec.
+NOTE: the test requires that /data/run-test/ exists and is writable and not mounted noexec.