DexPathList.Element.toString(): Fix unintended behavior change.

CL http://r.android.com/847393 accidentally changed behavior in
the case where both path != null and dexFile != null.

That behavior change was probably relatively harmless, but it was
unintentional. This CL changes back to the old behavior.

Test: Treehugger

Change-Id: I56d0ced49d7cbadf8f1b7e5619c0c3d9393e7431
1 file changed