staging: dgap: re-arrange functions for removing forward declarations

Re-arrange the functions for removing forward declarations.
Signed-off-by: NDaeseok Youn <daeseok.youn@gmail.com>
Tested-by: NMark Hounschell <markh@compro.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>