staging: dgap: fix checkpatch warnings

Remove a few spaces at beginning and end of line. Remove single statement
braces {}. Remove two FSF boilerplate paragraphs.

Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Cc: Lidza Louina <lidza.louina@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Scott H Kilau <Scott_Kilau@digi.com>
Cc: Eng.Linux@digi.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>