staging: dgnc: Remove unnecessary functions from dgnc_driver.c

This commit slightly cleans up the dgnc_driver.c file. The changes
include removing one-line proxy functions as they were not needed.
Additionaly the pci 'remove' function is deleted because it was no
need for it.

Signed-off-by: Konrad Zapalowicz <bergo.torino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>