examples: client: fix reading file from stdin
Created by: jneuhauser
I suggested that reading a file from stdin is in the client implemented because of the check and special handling for parameter "-" in the main function. My suggestion wasn´t true and open is called with "NULL" as filename instead of using "STDIN_FILENO" (=0) as file descriptor in the function send_file.
This pr fixes this issue.
I prefer to explicit set the file descriptor initially to "STDIN_FILENO" (=0) instead on relying on global variable initialization, as it make this behavior more clear.
Signed-off-by: Johann Neuhauser jneuhauser@dh-electronics.de