examples: files: retire cached code
examples: files: retire cached code

The new uncached device access interface is obviously the way
forward for all applications, start retiring the old method of
traversing the devices in the examples.

The output looks the same after this change, it just uses the
raw device interface to get the track listing iteratively.

Signed-off-by: Linus Walleij <67b0e6e4a7f8300bccd309fb10a9106ef3d7b5b0@df.lth.se>

jemc/libmtp,reverendhomer/libmtp,reverendhomer/libmtp,libmtp/libmtp,reverendhomer/libmtp,libmtp/libmtp,reverendhomer/libmtp,philipl/libmtp,philipl/libmtp,jemc/libmtp,philipl/libmtp,jemc/libmtp,jemc/libmtp,libmtp/libmtp