Documentation: Remove redundant file names from examples

Since most examples use the ddcmd alias, remove the redundant file names

Signed-off-by: Rex Nie <rex.nie@jaguarmicro.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231213073735.2850-1-rex.nie@jaguarmicro.com