Fix `list -af` example in documentation
Didn't work since $tracktotal is not an Album field
@@ -212,7 +212,7 @@ The ``-p`` option makes beets print out filenames of matched items, which might
be useful for piping into other Unix commands (such as `xargs`_). Similarly, the
``-f`` option lets you specify a specific format with which to print every album
or track. This uses the same template syntax as beets' :doc:`path formats
-<pathformat>`. For example, the command ``beet ls -af '$album: $tracktotal'
+<pathformat>`. For example, the command ``beet ls -af '$album: $albumtotal'
beatles`` prints out the number of tracks on each Beatles album. In Unix shells,
remember to enclose the template argument in single quotes to avoid environment
variable expansion.
