Staging: echo: remove annoying "end of function" markers

This patch removes the very noisy "end of function" markers that are
very annoying when reading the driver code.

Cc: David Rowe <david@rowetel.com>
Cc: Steve Underwood <steveu@coppice.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>